Answer: B) therefore.
Explanation: Transitions in a text help us to express more clearly the ideas. A transition is usually used to separate two independent clauses that are related between each other. In the given exercise, we have two clauses "The school board needs to represent a more diverse population" and "A student member should be elected to represent local youth" these independent clauses are related because the second one is the consequence of the first one, the transition that expresses this relation is "therefore."
