**Core Concept**
The digestion of fat-soluble vitamins involves the breakdown of esterified forms into their active, free forms. This process relies on enzymes that can hydrolyze the ester bonds, making the vitamins available for absorption.

**Why the Correct Answer is Right**
The correct answer involves pancreatic lipase, which is the primary enzyme responsible for breaking down triglycerides into free fatty acids and glycerol. However, pancreatic lipase does not directly break down the ester bonds of fat-soluble vitamins. Instead, a different enzyme, carboxyl ester lipase (CEL), also known as cholesterol esterase, plays a crucial role in the digestion of these vitamins. CEL is secreted by the pancreas and works in conjunction with pancreatic lipase to hydrolyze the ester bonds of fat-soluble vitamins, such as vitamins A, D, E, and K.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not specify the correct enzyme involved in the digestion of fat-soluble vitamins. While pancreatic lipase is essential for fat digestion, it is not the primary enzyme responsible for breaking down the ester bonds of these vitamins.
* **Option B:** This option is incorrect because it does not accurately describe the enzyme involved in the digestion of fat-soluble vitamins. While bile salts do play a role in fat digestion, they do not directly break down the ester bonds of these vitamins.
* **Option D:** This option is incorrect because it does not specify the correct enzyme involved in the digestion of fat-soluble vitamins. While gastric lipase does contribute to fat digestion, it is not the primary enzyme responsible for breaking down the ester bonds of these vitamins.

**Clinical Pearl / High-Yield Fact**
The digestion of fat-soluble vitamins requires a coordinated effort between pancreatic enzymes, including carboxyl ester lipase, and bile salts. Impairments in this process can lead to deficiencies in these essential nutrients, which can have significant clinical consequences.

**Correct Answer:** C. Carboxyl ester lipase.