**Core Concept**
The question relates to the concept of immunotherapy, specifically the use of monoclonal antibodies against tumor cells to target cancer. This involves the production of antibodies that bind to specific antigens on the surface of cancer cells, marking them for destruction by the immune system.

**Why the Correct Answer is Right**
The correct answer involves the use of monoclonal antibodies that target tumor cells. This is achieved through the process of monoclonal antibody production, where a specific clone of B cells is selected and expanded to produce large quantities of a single type of antibody. These antibodies can be designed to bind to specific tumor antigens, such as HER2 in breast cancer or CD20 in non-Hodgkin's lymphoma. Once bound to the tumor cells, the antibodies can trigger various immune responses, including complement activation, antibody-dependent cellular cytotoxicity (ADCC), and antibody-dependent cellular phagocytosis (ADCP).

**Why Each Wrong Option is Incorrect**
**Option A:** This option might refer to a type of chemotherapy or radiation therapy, which is a different approach to cancer treatment.
**Option B:** This option might refer to a type of immunosuppressive therapy, which would be counterintuitive in the context of targeting tumor cells.
**Option C:** This option might refer to a type of surgery or other localized treatment, which does not involve the use of antibodies to target cancer cells.

**Clinical Pearl / High-Yield Fact**
Monoclonal antibodies have revolutionized the treatment of various types of cancer, including breast cancer, non-Hodgkin's lymphoma, and colorectal cancer. They are often used in combination with other treatments, such as chemotherapy and targeted therapy, to achieve better outcomes.

**Correct Answer:** D. Rituximab.