Fill in the blanks with suitable prepositions:
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 A)at/ on is correct as they indicate a specific time and specific days respectively. The other options are wrong as in, about, and around indicate inside something, a piece information, and circular movement respectively. These uses don't fit in the given question. The correct answer is A)at/ on.