**Core Concept**
The lesser sac, also known as the omental bursa, is a peritoneal cavity located behind the stomach and the liver. Its boundaries are essential in understanding the anatomy and clinical relevance of the region. The lesser sac is bounded by several key structures, including the liver, the stomach, the colon, and the diaphragm.

**Why the Correct Answer is Right**
The correct boundaries of the lesser sac include the inferior surface of the liver (above), the stomach (below), the lesser omentum (containing the bile duct, hepatic artery, and portal vein) (anteriorly), and the greater omentum (posteriorly). The diaphragm forms the roof of the lesser sac. The correct boundaries are crucial in understanding the anatomy of the region and the approach to various clinical conditions, such as pancreatic and liver surgery.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe the boundaries of the lesser sac.
**Option B:** This option is incorrect because it does not include the lesser omentum as an anterior boundary.
**Option C:** This option is incorrect because it does not include the greater omentum as a posterior boundary.

**Clinical Pearl / High-Yield Fact**
The lesser sac is a clinically relevant region, as it is involved in various surgical procedures, such as pancreatic and liver surgery. Understanding its boundaries is essential in avoiding complications and ensuring successful outcomes.

**Correct Answer:** C. The lesser sac is bounded by the liver (above), stomach (below), lesser omentum (anteriorly), and greater omentum (posteriorly), with the diaphragm forming its roof.