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 C)on/in is correct as on and in indicate a surface and the inside of something respectively . The other options are wrong as at, into, and over indicate a specific location, movement towards the inside, and completion of a task respectively. These uses don't fit in the given question. The correct answer is C)on/in.