**Core Concept**
Embalming fluids are chemical solutions used to temporarily preserve the body after death, preventing decay and maintaining a lifelike appearance for viewing or medical examination. These fluids often contain a combination of disinfectants, preservatives, and moisturizers to prevent dehydration.

**Why the Correct Answer is Right**
Ethanol, or alcohol, is not typically used in embalming fluids due to its limited preservative properties and potential to dissolve or distort certain materials within the body. Formalin, a solution of formaldehyde, is commonly used as a preservative in embalming fluids to prevent bacterial growth and decay. Methanol, a solvent and preservative, is also used in some embalming fluids. Glycerin, a humectant, helps to prevent dehydration and maintain tissue moisture.

**Why Each Wrong Option is Incorrect**
**Option A:** Formalin is actually a key constituent of embalming fluid, serving as a potent preservative against decay and bacterial growth.
**Option B:** Methanol is indeed used in some embalming fluids, providing its solvent and preservative properties.
**Option D:** Glycerin is a common additive to embalming fluids, helping to maintain tissue moisture and prevent dehydration.

**Clinical Pearl / High-Yield Fact**
When working with embalming fluids, it is essential to wear protective gloves and eyewear, as these chemicals can cause skin irritation, allergic reactions, and even respiratory problems.

✓ Correct Answer: C. Ethanol. Ethanol is not a constituent of embalming fluid.