**Core Concept**
The question is testing knowledge of immunosuppressive drugs that inhibit Interleukin-2 (IL-2), a crucial cytokine involved in T-cell activation and proliferation. IL-2 plays a central role in the immune response, particularly in the context of cell-mediated immunity.

**Why the Correct Answer is Right**
IL-2 inhibitors work by blocking the activity of IL-2, which is essential for the growth and proliferation of T-cells. This mechanism is particularly useful in preventing transplant rejection and treating autoimmune diseases. The correct answer is an immunosuppressive drug that specifically targets the IL-2 pathway. This drug has been shown to reduce the activity of IL-2 receptor, thereby inhibiting the proliferation of T-cells.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it is not an IL-2 inhibitor. It may be a different type of immunosuppressive drug that targets a different pathway.
**Option B:** This option is incorrect because it is not an IL-2 inhibitor. It may be a drug that targets a different cytokine or immune pathway.
**Option C:** This option is incorrect because it is not an IL-2 inhibitor. It may be a drug that targets a different aspect of the immune response.

**Clinical Pearl / High-Yield Fact**
One high-yield fact to remember is that IL-2 inhibitors can increase the risk of infections due to their immunosuppressive effects. It is essential to monitor patients for signs of infection and adjust the dose or switch to a different immunosuppressive agent if necessary.

**Correct Answer: D. Basiliximab**