When an antigen-presenting cell interacts successfully with a helper T cell, the antigen-presenting cell secretes a signal molecule that assists in the activation of the helper T cell. This signal molecule is
A. interferon.
B. complement.
C. interleukin-1.
D. perforin.
Answer:C
When an antigen-presenting cell interacts successfully with a helper T cell, the antigen-presenting cell secretes a signal molecule that assists in the activation of the helper T cell. This signal molecule is
A. interferon. B. complement. C. interleukin-1. D. perforin.