Why don’t on duty lookouts realize right away the the titanic has hit an iceberg

They see the front of the ship miss the iceberg, so they think all is OK. They are not prepared for a crash.

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.

comment ur email above in the comments(: