**Core Concept:**
The fencing attitude of the dead bodies is a condition where the body assumes an unnatural, fencing-like posture due to rigor mortis, a series of natural changes in the body after death. Rigor mortis is a temporary stiffening of muscles that occurs due to the cessation of cellular activity and energy production after death.

**Why the Correct Answer is Right:**
Rigor mortis is a physiological response that occurs after death due to the loss of energy production in muscle cells. As the cells lose their ability to generate adenosine triphosphate (ATP) and calcium levels rise, the calcium ions bind to troponin and cause the myosin heads to bind to actin filaments, leading to muscle stiffness. This is known as the early phase of rigor mortis.

**Why Each Wrong Option is Incorrect:**
A. This option is incorrect because the fencing attitude is not caused by muscle rigor mortis, but rather by the stiffening posture that ensues due to the rigor mortis process.
B. This option is incorrect as it does not address the cause of the fencing attitude, which is rigor mortis. Muscle rigor mortis is a separate phenomenon that occurs after death, not a cause for the fencing attitude.
C. This option is incorrect because it is a misconception rather than explaining the actual cause of the fencing attitude. The fencing attitude is not caused by an animal's behavior, but by the physiological changes after death.
D. This option is incorrect because it does not address the fencing attitude and instead refers to a different issue related to the post-mortem changes.

**Clinical Pearl / High-Yield Fact:**
The fencing attitude is a misconception often associated with post-mortem examination of animals. It is not a cause for concern, but rather a result of the post-mortem changes, including rigor mortis. In practice, it is essential to differentiate between normal post-mortem changes and abnormal findings to avoid unnecessary worry or intervention in animal post-mortem examinations.