Tetraidothyronine is

Options

A. `T_(3)`
B. Thyroxine
C. TSH
D. TRH.

Answer

**Step-by-Step Solution:**

1. **Understanding the Term "Tetraidothyronine":**
- Tetraidothyronine is a term that refers to a specific thyroid hormone.

2. **Identifying the Options:**
- The options given are T3, thyroxine, TSH, and TRH. We need to determine which of these corresponds to tetraidothyronine.

3. **Analyzing the Options:**
- **T3**: This is known as triiodothyronine, which is not the same as tetraidothyronine.
- **Thyroxine**: This is also known as T4 or tetraidothyronine.
- **TSH**: This stands for thyroid-stimulating hormone, which is not a thyroid hormone itself but rather a hormone that stimulates the thyroid.
- **TRH**: This stands for thyrotropin-releasing hormone, which is secreted by the hypothalamus and regulates TSH release.

4. **Conclusion:**
- Based on the analysis, tetraidothyronine is synonymous with thyroxine (T4). Therefore, the correct answer is **thyroxine**.

**Final Answer:**
Tetraidothyronine is **thyroxine**.

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