One of the following is correct statement ?

Options

A. `T_(4)` is more active than `T_(3)`
B. `T_(3)` is more active than `T_(4)`
C. `T_(3)` and `T_(4)` are the same
D. None of these

Answer

To solve the question regarding which statement is correct about thyroid hormones T3 and T4, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Statements**:
- The question presents four statements about T3 and T4. We need to evaluate each statement to determine which one is correct.

2. **Evaluate the First Statement**:
- The first statement claims that T4 is more active than T3.
- **Analysis**: This statement is incorrect. T4 (Thyroxine) is less active compared to T3 (Triiodothyronine).

3. **Evaluate the Second Statement**:
- The second statement claims that T3 is more active than T4.
- **Analysis**: This statement is correct. T3 is indeed the more active thyroid hormone, and it binds quickly to nuclear receptors, leading to faster activation.

4. **Evaluate the Third Statement**:
- The third statement claims that T3 and T4 are the same.
- **Analysis**: This statement is incorrect. T3 and T4 are different hormones with distinct structures and functions.

5. **Evaluate the Fourth Statement**:
- The fourth statement is "none of these."
- **Analysis**: Since we have identified the second statement as correct, this option is also incorrect.

6. **Conclusion**:
- After evaluating all the statements, we conclude that the correct answer is the second statement: "T3 is more active than T4."

### Final Answer:
The correct statement is: **T3 is more active than T4.**

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