A nominative case points to the subject, not object, of the sentence, so it has to be that someone who did the action described in the sentence. Also, it has to be in the nominative form, that is "i, you, he, she, we, they"
Here the correct answer is c. The neighborhood kids and we waited for the parade.: the "we" is correct and it's also nominative.
in A and B and D we don't have a nominative case.
