At the time of interview, heart beat increased due to

Options

A. ADH secretion
B. Secretion of renin
C. Secretion of adrenaline
D. Adrenocorticotrophic hormone.

Answer

To answer the question "At the time of interview, heartbeat increased due to," we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Context**: The situation described is an interview, which can be a stressful event for many individuals. Stressful situations typically trigger physiological responses in the body.

2. **Understand the Role of Hormones**: During stress, the body releases certain hormones that prepare it to handle the situation. One of the primary hormones involved in the stress response is adrenaline (also known as epinephrine).

3. **Locate the Source of Adrenaline**: Adrenaline is secreted by the adrenal medulla, which is part of the adrenal glands located on top of the kidneys.

4. **Effects of Adrenaline**: When adrenaline is released into the bloodstream, it causes several physiological changes:
- Increased heart rate (tachycardia)
- Increased strength of heart contractions
- Enhanced alertness and readiness for action (fight-or-flight response)

5. **Evaluate Other Options**:
- **ADH secretion**: This hormone primarily regulates water balance and does not directly affect heart rate in the context of stress.
- **Secretion of renin**: Renin is involved in blood pressure regulation but is not the primary hormone responsible for increasing heart rate during stress.
- **Secretion of adrenocorticotropic hormone (ACTH)**: This hormone stimulates the adrenal cortex but is not directly responsible for the immediate increase in heart rate.

6. **Conclusion**: Given the context of an interview and the physiological response to stress, the increase in heartbeat is primarily due to the secretion of adrenaline.

### Final Answer:
The heartbeat increased at the time of the interview due to the secretion of adrenaline (option C).

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