Identify the real subject in the following sentence: The decision of the engineers was to double the chlorine concentration in the water treatment process.

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.

no. but, i heard its a good book. you could look up the answers or summary on some website.

again the answer is c