Which of the following sentences uses prepositions correctly?

a) the school bus finally arrived at the museum.

b) she might of gone to the party if it started earlier.

c) for years, my parents differed from each other on politics.

d) i sat between my mother, sister, and brother-in-law.

A) The school bus finally arrived at the museum.

Explanation: In sentence B, the preposition of should be replaced by the auxiliary verb have; in sentence C, the preposition on before the word politics should be replaced by the preposition in, and in sentence D, the preposition between cannot take three elements in this context, since you can only sit between two people (with or among would be more appropriate).

gregor's attempts to crawl on the walls