"you can't make up for lost time. you can only do better in the future" - ashley ormonwhat does it mean?

It means the time used in the past is already redundant, and that you can learn from the past to improve next time.  

some sort of sound device i believe.

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.