Which of the following causes cramps in our muscles during sudden activity ?

Options

A. Ethanol
B. Lactic acid
C. Carbon dioxide
D. Water .

Answer

### Step-by-Step Solution:

1. **Understanding Muscle Cramps**: Muscle cramps often occur during sudden physical activity or intense workouts. This is important to note as it sets the context for the question.

2. **Identifying the Cause**: During sudden activities, the muscles require more energy, which increases the demand for oxygen. If the oxygen supply is insufficient, the body resorts to anaerobic respiration.

3. **Anaerobic Respiration**: In the absence of sufficient oxygen, the body undergoes anaerobic respiration, which primarily occurs in the muscles during intense activity.

4. **Production of Lactic Acid**: Anaerobic respiration leads to the production of lactic acid as a byproduct. This accumulation of lactic acid in the muscles is what causes the cramps.

5. **Evaluating the Options**:
- Ethanol: Not related to muscle cramps.
- Lactic Acid: Correct answer, as it is produced during anaerobic respiration.
- Carbon Dioxide: Not a direct cause of cramps.
- Water: Not related to muscle cramps.

6. **Conclusion**: The correct answer to the question is **Lactic Acid**, which is responsible for causing cramps in our muscles during sudden activity.