## **Core Concept**
The question pertains to the primary target cells of the Human Immunodeficiency Virus (HIV), which causes AIDS (Acquired Immunodeficiency Syndrome). HIV specifically targets and infects a subset of lymphocytes crucial for immune response.

## **Why the Correct Answer is Right**
The correct answer, **CD4+ T cells (T-helper cells)**, is right because HIV primarily infects and destroys these cells. CD4+ T cells play a pivotal role in the immune system by helping to activate B cells to produce antibodies and cytotoxic T cells to kill infected cells. The virus enters these cells by binding to the CD4 receptor and a co-receptor, typically CCR5 or CXCR4, leading to the depletion of CD4+ T cells and subsequent immunocompromise.

## **Why Each Wrong Option is Incorrect**
- **Option A:** While B cells are crucial for the immune response, especially in producing antibodies, HIV does not directly infect B cells. However, B cell function can be indirectly affected by HIV infection.
- **Option B:** Neutrophils are a type of granulocyte and are part of the innate immune response. They are not the primary target of HIV.
- **Option C:** This option is not provided, but typically, other immune cells like macrophages can be infected by HIV. However, the primary and most well-known target cells are CD4+ T cells.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that the progression of HIV to AIDS is marked by a significant decline in CD4+ T cell count, typically below 200 cells/μL. This immunocompromised state predisposes individuals to opportunistic infections and certain cancers.

## **Correct Answer:** . CD4 T cell