I think 19,000 people are in the witness protection program.
I believe that most relevant answer in this item is:
b. people are normally capable of processing information faster than most people speak
Among the four choices above, we choose b rather a, c, and d. This is because this choice is rather correct than the other three.
Let us complete the sentence:
Information processing rate can be a barrier to listening because people are normally capable of processing information faster than most people speak
Thus,
the correct answer is B
