This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
CD4 count refers to 
Select and explain. 
A. T helper cells, B. B cells, C. Cytotoxic cells, D. Both B And T Cells
A: T helper cells
Answer: A: T helper cells 
Explanation: Helper T-cells → CD4 positive. o Cytotoxic T-cells and suppressor T-cells → CD 8 positive,
Based on function CD4 helper T cells are divided into1. Effector CP4 helper T-cells

Functions are- A.
By TH1 cells
i. Activate macrophages
ii. Delayed hypersensitivity
iii. Cell-mediated immunity
iv. The killing of intracellular microbes. e.g. tuberculosis and leprosy
v. Destruction of target cells by.
Activate CDS T cells to become cytotoxic cells. b. Activate NK cells B By TH2 celts
i) Activate B cells to develop into anybody producing plasma cells → facilitate the synthesis of antibodies.
2. Memory CD4 helper T cells □ Retain the antigenic affinity of the originally activated T cells and are used to act as later effector cells during a second immune response.