After the game ended, were you as disappointed us *** we
After the game ended, were you as disappointed as Us?
The correct word to complete the question is "us". Although "we" and "us" are pronouns that we use to refer to the first person plural, the difference is that "we" is a subject pronoun and "us" is an object pronoun, then as their names say they are used in the correct position in the formula according to what they represent. Us is an object in the question.
since it is asking for her reaction to elnora's trouble at school you can rule out any answers with a positive response (b). then you can rule out (d), this is because it does not show the mother's reaction but the daughter's response. that leaves you with two options (a) and (c), by looking at the options you can rule out (c) because it isn't referring back to elnora's issues at school.