Initially After an Infection, the Majority of the T Cells

Multiple Choice

Initially after an infection, the majority of the T cells present in the tissue at a site of infection are not specific for the infecting pathogen, but over the course of several days, this changes and antigen-specific T cells become enriched at this site. This is because:

A) T cells do not use their T-cell receptors during extravasation from blood into tissues.
B) Early after infection, there are few antigen-specific T cells in the host.
C) Naive T cells do not express the homing receptors to extravasate into sites of inflammation.
D) T cells up-regulate CD69 early after activation and are retained in the lymphoid organs.
E) T cells require several days to down-regulate CCR7.