The letter T-in T-lymphocyte refers to

Options

A. Thyroid
B. Thalamus
C. Tonsil
D. Thymus

Explanation

**Step-by-Step Solution:**

1. **Understanding Lymphocytes**: Begin by recognizing what lymphocytes are. They are a type of white blood cell that plays a crucial role in the immune system.

2. **Identifying Primary Lymphoid Organs**: Lymphocytes are produced in primary lymphoid organs, which include the thymus and bone marrow.

3. **Focusing on T-Lymphocytes**: T-lymphocytes are a specific type of lymphocyte.

4. **Source of T-Lymphocytes**: T-lymphocytes are produced in the thymus gland. This is key to understanding what the "T" stands for in T-lymphocyte.

5. **Conclusion**: Since T-lymphocytes are derived from the thymus, the letter "T" in T-lymphocyte refers to the thymus.

6. **Final Answer**: Therefore, the correct answer is option D: thymus.

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