In each of the questions given below four words are given in bold. These four words may or may not be in their correct position. The sentence is then followed by options with the correct combination of words that should replace each other in order to make the sentence grammatically and contextually correct. Find the correct combination of the words that should interchange. If the sentence is correct as it is then, select option “No interchange required” as your choice.

There are some careers (A) where you can’t afford (B) to make even the most disastrous (C) mistake without infinitesimal (D) consequences.

The correct answer is C-D.

Let's analyze the given sentence and the positions of the bold words to determine if they need to be interchanged:
"There are some careers (A) where you can’t afford (B) to make even the most disastrous (C) mistake without infinitesimal (D) consequences."

1. The placement of "careers" (A) and "afford" (B) is contextually and grammatically appropriate. "Careers" is a plural noun serving as the subject of the clause, and "can't afford to" is a standard English idiom meaning to be unable to do something because it would cause problems.

2. Now let's examine "disastrous" (C) and "infinitesimal" (D):
- "Disastrous" means causing great damage or harm.
- "Infinitesimal" means extremely small or negligible.
- Reading the sentence with these definitions, it says: "...make even the most disastrous (extremely damaging) mistake without infinitesimal (extremely small) consequences." This is logically contradictory. If a mistake is extremely damaging, the consequences cannot be described as "without infinitesimal consequences" to mean serious. Rather, the sentence intends to convey that in certain careers, even an extremely small ("infinitesimal") mistake cannot be made because it will lead to extremely damaging ("disastrous") consequences.

3. If we swap C and D, the sentence becomes:
"There are some careers (A) where you can’t afford (B) to make even the most infinitesimal (D) mistake without disastrous (C) consequences."

This replacement makes the sentence perfectly logical and contextually correct: in high-stakes careers, even a tiny (infinitesimal) error can lead to catastrophic (disastrous) outcomes.