Which of the following correctly describes the physical interaction between an antigen-presenting cell and a naive helper T-lymphocyte during activation?
a) Antigen-presenting cell releases cytokines to inhibit T-cell activation.
b) Naive T-lymphocyte directly engulfs the antigen-presenting cell.
c) T-cell receptor recognizes the antigen presented by the antigen-presenting cell.
d) Antigen-presenting cell phagocytoses the naive T-lymphocyte.