Mammalian thymus' is mainly concerned with

Options

A. Regulation of body temperature
B. Regulation of body growth
C. Immunological functions
D. Secretion of thyrotropin

Answer

### Step-by-Step Solution:

1. **Understanding the Thymus Gland**: The thymus is a specialized organ located in the chest, between the lungs. It plays a crucial role in the immune system, particularly during the early stages of life.

2. **Evaluating the Options**:
- **Option A: Regulation of Body Temperature**: This function is primarily managed by the skin and sweat glands, not the thymus. Therefore, this option is incorrect.
- **Option B: Regulation of Body Growth**: Growth regulation is mainly controlled by hormones such as luteinizing hormone and follicle-stimulating hormone, which are secreted by the pituitary gland. Thus, this option is also incorrect.
- **Option C: Immunological Functions**: The thymus is responsible for the maturation of T-lymphocytes (T-cells), which are vital components of the immune system. They help the body fight infections. This option is correct.
- **Option D: Secretion of Thyrotropin**: Thyrotropin (TSH) is a hormone that stimulates the thyroid gland to produce thyroxine. This function is not related to the thymus gland, making this option incorrect as well.

3. **Conclusion**: After evaluating all the options, the thymus is mainly concerned with immunological functions, specifically the production and maturation of T-cells.

### Final Answer:
The mammalian thymus is mainly concerned with **immunological functions** (Option C).

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