**Core Concept**
Burkitt's lymphoma is a type of aggressive non-Hodgkin lymphoma characterized by its rapid growth rate and high mitotic activity. It is primarily a B-cell malignancy, often arising in the jaw or abdomen, and is associated with Epstein-Barr virus (EBV) infection in a significant proportion of cases.

**Why the Correct Answer is Right**
The correct answer is **C. High cell turnover and rapid growth rate**. Burkitt's lymphoma is known for its high cell turnover and rapid growth rate, which is a result of the overexpression of the c-Myc oncogene. The c-Myc protein plays a crucial role in cell proliferation and apoptosis, and its overexpression leads to uncontrolled cell growth and tumor formation. Additionally, the rapid growth rate of Burkitt's lymphoma results in a high mitotic index, which is a characteristic feature of this malignancy.

**Why Each Wrong Option is Incorrect**
**Option A:** Not accurate, as Burkitt's lymphoma is not typically associated with a low cell turnover and slow growth rate.

**Option B:** Incorrect, as Burkitt's lymphoma is primarily a B-cell malignancy, but it is not exclusively associated with T-cell receptor gene rearrangements.

**Option D:** Not true, as Burkitt's lymphoma is not typically associated with a low mitotic index and slow growth rate.

**Clinical Pearl / High-Yield Fact**
Burkitt's lymphoma is a highly aggressive malignancy that requires prompt treatment with chemotherapy, radiation therapy, or autologous stem cell transplantation. The use of rituximab, a monoclonal antibody targeting CD20, has improved outcomes in patients with Burkitt's lymphoma.

**Correct Answer:** C. High cell turnover and rapid growth rate.