## **Core Concept**
Rigor mortis, also known as postmortem rigidity, is a well-known phenomenon that occurs after death. It is characterized by temporary stiffening of muscles due to chemical changes within the muscle tissue. This process begins to set in around 2-4 hours after death, peaks at 12-18 hours, and then gradually resolves.

## **Why the Correct Answer is Right**
The resolution of rigor mortis, or the disappearance of postmortem rigidity, typically starts in the smaller muscles and progresses to the larger ones. The **face and neck muscles** are among the first to relax, which usually happens within 24-36 hours after death, depending on environmental conditions. This sequence is related to the size of the muscle groups and the rate of autolytic changes.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because, generally, larger muscle groups take longer to relax compared to smaller ones.
- **Option B:** This option is incorrect because while muscles in the limbs do relax, they typically do so after the smaller muscles of the face and neck.
- **Option C:** This option is incorrect because the resolution starting in the trunk muscles does not accurately reflect the typical sequence of rigor mortis resolution.
- **Option D:** This option is incorrect because it does not accurately represent the sequence or location of the first muscles to relax.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that the onset and resolution of rigor mortis can be influenced by environmental factors such as temperature. Higher temperatures can accelerate the process, while lower temperatures can slow it down. Understanding the sequence and timing of rigor mortis can be helpful in estimating the post-mortem interval.

## **Correct Answer:** .