Which of the following statement(s) is/are CORRECT for antigen activated effector T cells?
- $CD4^+$ cells make contact with macrophages and stimulate their microbicidal activity.
- $CD4^+$ cells make contact with B cells and stimulate them to differentiate into plasma cells.
- $CD8^+$ cells make contact with B cells and stimulate them to differentiate into plasma cells.
- $CD8^+$ cells make contact with virus infected cells and kill them
- $Q$ only
- $Q$ and $S$ only
- $P, Q$ and $S$ only
- $P, Q, R$ and $S$