Which of the following statements is correct ?

Options

A. Some tranquilizers function by inhibiting the enzymes which catalyse the degradation of noradrenaline.
B. Tranquilizers are narcotic drugs.
C. Tranquilizers are chemical compounds that do not effect the message transfer from nerve to receptor .
D. Tranquilizers are chemical compounds that can relieve pain and fever.

Explanation

To determine which statement about tranquilizers is correct, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Analyze Option 1**: "Some tranquilizers function by inhibiting the enzymes which catalyze the degradation of noradrenaline."
- **Explanation**: Noradrenaline is a neurotransmitter that plays a significant role in mood regulation. Tranquilizers can act as antidepressants by inhibiting the enzymes that break down noradrenaline, allowing it to remain active longer and improve mood. This statement is correct.

2. **Analyze Option 2**: "Tranquilizers are the narcotics."
- **Explanation**: Tranquilizers are not classified as narcotics. Narcotics typically refer to drugs that induce sleep and relieve pain, while tranquilizers are primarily used to reduce anxiety and promote calmness. This statement is incorrect.

3. **Analyze Option 3**: "Tranquilizers are chemical compounds that do not affect the message transfer from the nerve to receptor."
- **Explanation**: This statement is misleading. Tranquilizers do affect message transfer by modulating neurotransmitter levels, particularly noradrenaline, which influences communication between nerves and receptors. Therefore, this statement is incorrect.

4. **Analyze Option 4**: "Tranquilizers are chemical compounds that can relieve pain and fever."
- **Explanation**: This statement is incorrect as well. Tranquilizers are not primarily used for pain relief or fever reduction; they are used to manage anxiety and mood disorders.

### Conclusion:
After analyzing all the options, the correct statement is **Option 1**: "Some tranquilizers function by inhibiting the enzymes which catalyze the degradation of noradrenaline."

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