**Core Concept**
Volvulus refers to the twisting of a portion of the intestine around its mesenteric attachment, leading to intestinal obstruction and potential ischemia. The common sites of volvulus are typically areas where the mesentery is relatively long and mobile, allowing for twisting.

**Why the Correct Answer is Right**
The sigmoid colon is the most common site for volvulus, accounting for approximately 70% of cases. This is due to its relatively long mesentery, which allows for a greater degree of mobility and twisting. The sigmoid colon's mesentery is also more prone to redundancy, making it more susceptible to volvulus. The twisting of the sigmoid colon can lead to a decrease in blood flow to the affected segment, resulting in ischemia and potential necrosis.

**Why Each Wrong Option is Incorrect**
* **Option A:** The small intestine is a less common site for volvulus, and when it does occur, it is more likely to be a midgut volvulus, which is a different entity from sigmoid volvulus.
* **Option B:** The cecum is a rare site for volvulus, and when it does occur, it is often associated with other underlying conditions such as a redundant cecum or a malrotation of the gut.
* **Option C:** The transverse colon is not a typical site for volvulus, and when it does occur, it is often associated with other underlying conditions such as a redundant colon or a previous surgical intervention.

**Clinical Pearl / High-Yield Fact**
It is essential to recognize the clinical presentation of sigmoid volvulus, which often includes abdominal pain, bloating, and a characteristic "bird's beak" appearance on barium enema. Early recognition and treatment are crucial to prevent ischemia and potential necrosis.

**Correct Answer:** C.