**Core Concept**
The digestion of dietary fats involves several key components, including enzymes and bile salts. **Lipolysis**, the breakdown of fats into fatty acids and glycerol, is facilitated by **enzymes** such as gastric lipase and pancreatic lipase. **Bile salts** play a crucial role in **emulsification**, the process of breaking down fats into smaller particles to increase the surface area for enzymatic action.

**Why the Correct Answer is Right**
The correct answer involves components directly involved in the digestion of dietary fats. **Pancreatic lipase** breaks down triglycerides into fatty acids and glycerol, while **bile salts** emulsify fats, and **colipase** helps to stabilize pancreatic lipase activity in the presence of bile salts. **Gastric lipase** also contributes to fat digestion, particularly in the stomach.

**Why Each Wrong Option is Incorrect**
**Option A:** Bile pigments are not directly involved in fat digestion; they are products of bilirubin metabolism.
**Option B:** While gastric lipase does play a role in fat digestion, it is not the only or most critical component when considering the broader process involving pancreatic lipase, colipase, and bile salts.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that **bile salts** are crucial for the emulsification of fats, significantly enhancing the efficiency of **lipase** enzymes in breaking down dietary fats.

**Correct Answer:** D. Bile salts, Colipase, Gastric lipase, Pancreatic lipase.