Concept:A wet blanket is a person who spoils other people's enthusiasm or discourages them.Solution:Auntie Araba tells Afua to stop being a wet blanket because her brother needs support. So Afua had been discouraging her brother: she liked to discourage him.The idiom has nothing to do with washing (B), and it is about discouraging, not being weak (C) or simply not caring (A).Answer:Option D (liked to discourage)