**Core Concept**
Puppe's rule is a principle in forensic medicine that helps in determining the sequence of events, particularly in cases of multiple impact injuries. It is used to establish the order in which injuries were sustained, aiding in the reconstruction of the events surrounding a crime or accident.

**Why the Correct Answer is Right**
Puppe's rule states that in cases of multiple impact injuries, the injury that is most severe or has the most significant impact will be located closest to the point of entry or exit of the force. This is because the force of the impact is dissipated as it travels through the body, causing less severe injuries at a distance. The rule helps investigators to reconstruct the sequence of events and understand the dynamics of the injury. By analyzing the location and severity of the injuries, forensic experts can determine the order in which they were sustained.

**Why Each Wrong Option is Incorrect**
**Option A:** Chemical injuries are not related to Puppe's rule, which deals specifically with physical trauma and impact injuries.
**Option C:** Sexual assault is a different field of forensic investigation altogether, and Puppe's rule is not applicable in this context.
**Option D:** Percentage of burns is a concept related to burn injuries, not multiple impact injuries, and is not related to Puppe's rule.

**Clinical Pearl / High-Yield Fact**
Puppe's rule is an important principle in forensic medicine that helps investigators to reconstruct the sequence of events in cases of multiple impact injuries. It is essential to remember that the severity of the injury is directly related to the force of the impact and the distance from the point of entry or exit.

**✓ Correct Answer: B. Multiple impact injuries**