Select the most appropriate option that can substitute the underlined segment in the given sentence.
I will require a quiet room to work at.

The correct answer is in.

Explanation:

In the given sentence, the preposition used after "work" needs to correctly relate to "a quiet room".

We use the preposition "in" when referring to being enclosed or inside a location, space, or room (e.g., "in a room", "in a office", "in a building").

Therefore, the segment "work at" should be substituted with "work in" to make the sentence grammatically correct: "I will require a quiet room to work in."

Analysis of other options:
- with: Used to indicate accompaniment or using a tool/instrument.
- about: Used to indicate subject matter or concerning something.
- on: Used for surfaces or specific topics, but not for being inside a room.