Please help me with this question

A(n) __ clause should always be separated from the rest of the sentence by commas

Which sentence features a correctly identified compound pronoun in a prepositional phrase? a)she and i will be at the park on tuesday, waiting for mariah and them. b)the gift grandmother brought was for me and him. c)everyone is so sure that he'll be late after traveling with peter and maria. d)after they visit the grand canyon, tianna and mom are going to a spa.

Why does the green knight laugh at their response