Read the following details carefully and answer the questions that follow.

Nine consultants are assigned to three different departments: Department Alpha, Department Beta, and Department Gamma. Not less than two consultants and not more than four consultants work in any department. David works only with Emily, but not in department Beta. Frank works in department Beta but not with Ivy. Jack, Karen, and Leo work in the same department. Karen works with Ivy but not in department Alpha. Grace and Henry are two of the consultants.

Which of the following statements is true?

To determine which statement is true, let us analyze the given conditions step-by-step and deduce the exact department assignment for each of the 9 consultants: David, Emily, Frank, Grace, Henry, Ivy, Jack, Karen, and Leo.

1. Basic Rules & Structure:
- Total consultants = 9.
- Departments = Alpha, Beta, Gamma.
- Number of consultants per department = Between 2 and 4 (inclusive).

2. Deductions from Statements:
- "David works only with Emily, but not in department Beta."
This means David and Emily are the ONLY two consultants in their department (since David works only with Emily). Since they do not work in Beta, their department must be either Alpha or Gamma.
Thus, one department has exactly 2 consultants: {David, Emily}.

- "Jack, Karen, and Leo work in the same department."
So {Jack, Karen, Leo} form a group of 3 people in one department.

- "Karen works with Ivy but not in department Alpha."
This means Ivy is in the same department as Karen. Since Karen is already grouped with Jack and Leo, Ivy joins them! So this department has 4 consultants: {Jack, Karen, Leo, Ivy}.
Since Karen does not work in Alpha, this group of 4 must be in Beta or Gamma.

- "Frank works in department Beta but not with Ivy."
Since Frank is in Beta and Ivy is not in Beta, the 4-person group {Jack, Karen, Leo, Ivy} CANNOT be in department Beta. Therefore, the 4-person group must be in Department Gamma!

3. Final Department Assignment:
- Department Gamma (4 consultants): Jack, Karen, Leo, Ivy.
- Department Alpha (2 consultants): David, Emily (since David works only with Emily and cannot be in Beta).
- Department Beta (3 consultants): The remaining consultants must be in Beta. The remaining consultants are Frank, Grace, and Henry.
So, Department Beta has {Frank, Grace, Henry}.

4. Evaluating the Options:
- Leo works in department Gamma: True (Jack, Karen, Leo, and Ivy are in Gamma).
- Grace and Henry work in the same department: True (Both are in department Beta with Frank).
- Frank works in department Beta: True (Given directly in the problem).
- Four consultants work in department Gamma: True (Jack, Karen, Leo, Ivy).
- All are correct: True.

The correct answer is All are correct.