Choose the most appropriate preposition from the options given below for blank [2].
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 C)at is correct as it indicates a specific location. The other options are wrong as in, on, and within indicate the inside of something, a surface, including the inside of something respectively. These uses don't fit in the given question. The correct answer is C)at.