**Core Concept**
The inverse stretch reflex is a reflex that occurs in response to a sudden release of tension in a muscle, leading to a contraction of the muscle. This reflex is mediated by specialized receptors that detect changes in muscle length.

**Why the Correct Answer is Right**
The correct answer is the muscle spindle receptor, specifically the **intrafusal muscle spindle receptor**. These receptors are composed of specialized muscle fibers that are innervated by sensory neurons. When the muscle is stretched, the intrafusal muscle spindle receptors are activated, leading to a contraction of the muscle. However, in the case of an inverse stretch reflex, the sudden release of tension in the muscle leads to a contraction of the muscle, which is mediated by the activation of the intrafusal muscle spindle receptors.

**Why Each Wrong Option is Incorrect**
**Option A:** This option should be a receptor type that is not involved in the inverse stretch reflex, such as the **mechanoreceptor**. While mechanoreceptors are involved in detecting changes in muscle length, they are not specifically responsible for the inverse stretch reflex.

**Option B:** This option should be a receptor type that is involved in a different type of reflex, such as the **proprioceptor**. Proprioceptors are involved in detecting changes in muscle length and joint position, but they are not specifically responsible for the inverse stretch reflex.

**Option C:** This option should be a receptor type that is not involved in the inverse stretch reflex, such as the **nociceptor**. Nociceptors are involved in detecting painful stimuli, but they are not specifically responsible for the inverse stretch reflex.

**Clinical Pearl / High-Yield Fact**
The inverse stretch reflex is an important mechanism for maintaining muscle tone and preventing muscle atrophy. It is also an important factor in the development of muscle spasms and cramps.

**Correct Answer: C. Nociceptor**