Okay, let's tackle this question. The user is asking which drug isn't part of the 'Triple Therapy' immunosuppression for post-renal transplant patients. First, I need to recall what the standard triple therapy regimen includes. From what I remember, the typical drugs used are a calcineurin inhibitor (like cyclosporine or tacrolimus), an antimetabolite (such as mycophenolate mofetil), and a corticosteroid (like prednisone). Sometimes, a third drug might be a mTOR inhibitor instead of an antimetabolite, but the core three are usually those.

Now, looking at the options, the correct answer is the one that's not part of these three. Let's say the options were A. Cyclosporine, B. Mycophenolate, C. Prednisone, D. Azathioprine. Wait, but Azathioprine is an antimetabolite, so maybe it's an alternative to mycophenolate. However, if the question lists Azathioprine as an option, then it's part of the triple therapy in some cases. Hmm, maybe the options include a drug like sirolimus, which is an mTOR inhibitor. Or perhaps a drug like everolimus. Alternatively, maybe the options include a drug that's not in the standard triple therapy, such as a monoclonal antibody like basiliximab, which is used as induction therapy, not maintenance.

Wait, the user didn't provide the actual options. The original question has options A to D, but they're empty. The correct answer is supposed to be one of them. Since the user provided the correct answer as, say, C. Prednisone, but that's part of the triple therapy. Wait, maybe the correct answer is a drug like azathioprine if the standard is mycophenolate. Or maybe the options include a drug like cyclophosphamide, which isn't part of the triple therapy. But without the actual options, it's a bit tricky. However, the user's correct answer is not specified here. Wait, in the initial problem, the user wrote the correct answer as "C. Prednisone", but that can't be right because prednisone is part of the triple therapy. So perhaps there's a mistake here. Alternatively, maybe the question is about which is not part of the triple therapy, and the correct answer is a drug like cyclophosphamide, which is used in other contexts like cancer or autoimmune diseases but not in standard immunosuppression for transplants.

Wait, the user's correct answer is missing in the input. Let me check again. The user wrote:

**Correct Answer:** .

So the correct answer is missing. Hmm. Maybe in the original question, the options included a drug like sirolimus, which is sometimes used as a third agent instead of an antimetabolite, but in standard triple therapy, the third is typically a corticosteroid. Wait, maybe the options include a drug like leflunomide, which is an antimetabolite but not used in transplant immunosuppression. Alternatively, maybe the options have a drug like tacrolimus (which is part of the therapy), so if the options are A. Tacrolimus, B. Mycophenolate

✓ Correct Answer: C. FK 506