**Core Concept**
Embalming fluid introduction requires understanding of the human circulatory system, particularly the arterial system. The goal is to ensure proper perfusion and distribution of the embalming fluid to prevent tissue discoloration and decomposition.

**Why the Correct Answer is Right**
When encountering difficulty due to an arterial system problem, the embalming fluid should be introduced through the venous system, rather than the arterial system. This approach ensures that the fluid is distributed throughout the body via the venous circulation, which eventually returns to the heart, thereby achieving systemic perfusion. This method helps to prevent the fluid from being pushed back into the arterial system, which can lead to embolism.

**Why Each Wrong Option is Incorrect**
**Option A:** Introducing the embalming fluid through an arterial system problem would exacerbate the issue, leading to potential embolism and incomplete perfusion.
**Option B:** The question does not specify a problem with the venous system, making introduction through the venous system unnecessary.
**Option C:** This option is vague and does not provide a clear solution to the arterial system problem.

**Clinical Pearl / High-Yield Fact**
When performing embalming, it's essential to understand the circulatory system and the consequences of introducing embalming fluid through the arterial system. This knowledge helps prevent embolism and ensures proper tissue preservation.

**Correct Answer:** D.