Fill in the blanks with the most appropriate words.
___ your father ___ at the Medical College?
Yes, he does.
A preposition is a word which comes before a noun or a pronoun and establishes a relationship between the elements of a clause or words.
Option D is correct as the subject is singular and the question talks about a fact. Therefore, it must use the simple present tense.
The other options are wrong as no other tense can be used here.
The correct answer is D)does/work.