**Core Concept**
Gastric lymphoma, also known as stomach lymphoma, is a rare type of cancer that arises from the immune cells (lymphocytes) in the stomach lining. It is a distinct entity from gastric adenocarcinoma, another type of stomach cancer. Gastric lymphoma can be primary (originating in the stomach) or secondary (spread from another lymphomatous site).

**Why the Correct Answer is Right**
The standard treatment for gastric lymphoma involves a combination of chemotherapy and radiation therapy, rather than surgery alone. Total gastrectomy, which involves removing the entire stomach, is not typically recommended as a primary treatment approach for gastric lymphoma. Instead, treatment usually involves a multidisciplinary approach, including chemotherapy and radiation therapy to eliminate the cancer cells. The goal of treatment is to achieve a complete remission, and surgery may be considered in certain cases to remove any residual tumor or to address complications.

**Why Each Wrong Option is Incorrect**
**Option A:** The stomach is indeed a common site for gastric lymphoma, but it is not the most common site. The small intestine is the most common site for gastrointestinal lymphomas.

**Option B:** H. pylori infection is associated with gastric adenocarcinoma, but its role in gastric lymphoma is less clear. While H. pylori infection may contribute to the development of gastric lymphoma, it is not a primary cause.

**Option D:** The 5-year survival rate for gastric lymphoma can vary depending on the specific subtype and stage of the disease, as well as the effectiveness of treatment. However, a 5-year survival rate of 60% is not a universally accepted estimate.

**Clinical Pearl / High-Yield Fact**
In the management of gastric lymphoma, the choice of treatment depends on the specific subtype of lymphoma, the stage of the disease, and the patient's overall health status. A multidisciplinary approach, including chemotherapy, radiation therapy, and possibly surgery, is often necessary to achieve the best possible outcome.

**✓ Correct Answer: C. Total gastrectomy with adjuvant chemotherapy is the treatment of choice**