The correct option is A for
The preposition "for" is used to indicate the use, reason or purpose of something. The context refers to a query and "for" indicates the purpose of that inquiry. Thus, option B is correct.
"Of" indicates belonging to, relating to or being connected with something. The context does not require this preposition.
"From" indicates the point in space from which something originates.
"To" is used to indicate the place, person or thing that someone or something moves toward, or the direction of something.