Which of the following is a characteristic of the third line of defense that makes it significantly different from the second line?

A) The response is specific to a single antigen.
B) The initial response is very rapid, beginning in minutes to a couple of hours.
C) The response is effective on a broad range of antigens.
D) The response to a second exposure is similar to the response to a first exposure.
E) The responding cells are a variety of cell types.