Read the given information carefully and answer the questions that follow:

Eight professionals—A, B, C, D, E, F, G, and H—hold different positions in an organization: Intern, Analyst, Specialist, Manager, Director, VP, SVP, and CEO, listed in increasing order of seniority where Intern is the lowest rank and CEO is the highest rank. Each person works in a different department: IT, Finance, HR, Legal, Sales, Marketing, Audit, and R&D, though not necessarily in the same order.

Exactly three persons are senior to A. The person who works in HR is two posts junior to A. Three designations exist between the person who works in HR and F. G is immediately senior to the person who works in Legal, but is junior to A. H is senior to G but junior to F, and does not work in HR. The number of persons senior to H is equal to the number of persons junior to the one who works in IT. E is three posts senior to C. The person who works in Finance is immediately senior to B. The person who works in Sales is two posts senior to E. H does not work in R&D, and the person who works in Marketing is senior to the person who works in Audit.

In which of the following departments does the Manager work?

The correct option is Audit.

To determine the department in which the Manager works, we can step-by-step deduce the rank and department of each professional based on the given conditions.

Step 1: Establish the Seniority Hierarchy
There are eight positions listed in increasing order of seniority:
1. Intern (Lowest Rank)
2. Analyst
3. Specialist
4. Manager
5. Director
6. VP
7. SVP
8. CEO (Highest Rank)

Step 2: Place A, HR, and F
- "Exactly three persons are senior to A."
Since CEO, SVP, and VP are senior to Director, A must be the Director (Rank 5).
- "The person who works in HR is two posts junior to A."
Two posts junior to Director (Rank 5) is Specialist (Rank 3). Thus, the person in HR is at Rank 3.
- "Three designations exist between the person who works in HR and F."
The designations between Rank 3 and Rank 7 are Ranks 4, 5, and 6. Therefore, F must be the SVP (Rank 7).

Step 3: Determine the positions of H and IT
- "The number of persons senior to H is equal to the number of persons junior to the one who works in IT."
Let $R\left(H\right)$ be the rank of H and $R\left(\text{IT}\right)$ be the rank of the IT professional. The number of persons senior to H is $8-R\left(H\right)$ and junior to IT is $R\left(\text{IT}\right)-1$.
Equating them gives:

$8-R\left(H\right)=R\left(\text{IT}\right)-1\Rightarrow R\left(H\right)+R\left(\text{IT}\right)=9$

- We know H is junior to F (Rank 7) and senior to G (who is junior to A). So H can be Rank 6 or Rank 4.
If H were Rank 6, then IT would be Rank 3. But Rank 3 is already HR, which is a contradiction. Hence, H must be Rank 4 (Manager) and IT must be Rank 5 (Director, which is A).

Step 4: Determine E and C
- "E is three posts senior to C."
The difference between their ranks is 3. The available ranks satisfying this condition are Rank 6 (VP) for E and Rank 3 (Specialist) for C.
Thus, C is the Specialist who works in HR, and E is the VP (Rank 6).

Step 5: Determine G, Legal, B, Finance, and D
- "G is immediately senior to the person who works in Legal, but is junior to A" and "H is senior to G".
Since H is Rank 4, G must be Rank 2 (Analyst). Therefore, the person in Legal is Rank 1 (Intern).
- "The person who works in Finance is immediately senior to B."
B cannot be CEO (Rank 8), so B is the Intern (Rank 1) in Legal. Finance is immediately senior to B, so G (Analyst, Rank 2) works in Finance.
- The remaining professional D must be the CEO (Rank 8).

Step 6: Determine Sales, Marketing, Audit, and R&D
- "The person who works in Sales is two posts senior to E."
E is Rank 6 (VP), so Sales is Rank 8 (CEO, D).
- The remaining unassigned ranks for departments are Rank 7 (F), Rank 6 (E), and Rank 4 (H).
- "H does not work in R&D" means Rank 4 cannot be R&D. Thus, R&D must be assigned to Rank 6 or Rank 7.
- "The person who works in Marketing is senior to the person who works in Audit."
This means between Marketing and Audit, Audit must take the lower available rank, which is Rank 4 (Manager).

Hence, the Manager (H) works in the Audit department.