**Core Concept**
The question tests the understanding of immunosuppressive drugs and their additional properties, specifically anticancer activity. Immunosuppressive drugs are used to prevent organ rejection in transplant patients and to treat autoimmune diseases. However, some immunosuppressive drugs also exhibit anticancer properties.

**Why the Correct Answer is Right**
The correct answer is a drug that primarily functions as an immunosuppressant without significant anticancer activity. This drug works by inhibiting the activation of T-lymphocytes, which play a crucial role in cell-mediated immunity. By suppressing the immune system, this drug prevents the rejection of transplanted organs. Unlike other immunosuppressants, this drug does not have a notable effect on cancer cells, making it an ideal choice for patients at risk of organ rejection.

**Why Each Wrong Option is Incorrect**
**Option A:** This drug is known for its anticancer activity, making it an incorrect choice.
**Option B:** This drug has a dual mechanism of action, both as an immunosuppressant and anticancer agent, which contradicts the question's requirement.
**Option C:** This drug is primarily used as an anticancer agent and has some immunosuppressive properties, but its primary indication is not as an immunosuppressant.

**Clinical Pearl / High-Yield Fact**
When choosing an immunosuppressive drug, it's essential to consider the patient's risk of cancer and other comorbidities. Some immunosuppressants can increase the risk of certain cancers, so careful selection is necessary to minimize these risks.

**Correct Answer:** C. This drug is used as an immunosuppressive but lacks anticancer activity.