Following muscle contraction in response to a stimulus, the muscle temporarily cannot respond. This is known as:

Options

A. refractory period
B. motor end plate
C. oxygen debt
D. summation period

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the period following muscle contraction during which the muscle cannot respond to further stimuli.

2. **Identifying Key Terms**: The options provided are:
- Refractory period
- Motor end plate
- Oxygen debt
- Summation period

3. **Analyzing Each Option**:
- **Refractory Period**: This is the time after a muscle has contracted during which it cannot respond to another stimulus. This occurs due to factors like fatigue and lactic acid buildup when muscles are overworked.
- **Motor End Plate**: This refers to the neuromuscular junction where the nerve meets the muscle. It is not a period of non-responsiveness.
- **Oxygen Debt**: This term describes the temporary lack of oxygen during intense exercise but does not specifically refer to the inability of muscles to respond.
- **Summation Period**: This refers to the additive effect of multiple stimuli on muscle contraction, not a period of non-responsiveness.

4. **Conclusion**: The correct answer is the **Refractory Period**, as it specifically describes the temporary inability of the muscle to respond after contraction.

**Final Answer**: The muscle temporarily cannot respond following contraction due to the **Refractory Period**.

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