What speaker are you talking about?
To conclude means to finish or wrap up
D. When you and your friends hear this recording, it will be exciting.
An antecedent, by definition, is a word or a phrase that is referred to by an element that follows it in the same sentence or paragraph, typically. When we look at item “D,” we are left with the question: “What will be exciting?” Because “it” could be anything, it is safe to say that the antecedent is missing.