**Core Concept**
The question is testing the student's knowledge of the side effect profile and monitoring requirements of Disease-Modifying Antirheumatic Drugs (DMARDs), specifically those that impact liver function. This requires an understanding of the pharmacology of these medications and their potential hepatotoxic effects.

**Why the Correct Answer is Right**
Leflunomide and Sulfasalazine are known to cause hepatotoxicity, and as such, liver function tests (LFTs) are required before starting these medications and periodically during treatment. Leflunomide is metabolized by the liver and can cause elevations in liver enzymes, while Sulfasalazine can cause a hypersensitivity reaction that may manifest as hepatitis. Regular monitoring of LFTs is essential to prevent liver damage.

**Why Each Wrong Option is Incorrect**
* **Option A:** Methotrexate can cause hepatotoxicity, but it is not as commonly associated with liver damage as Leflunomide and Sulfasalazine. While LFTs are still required, the risk is lower.
* **Option B:** Hydroxychloroquine is generally well-tolerated and does not require regular LFT monitoring.
* **Option C:** Cyclosporine can cause nephrotoxicity and hypertension but is not typically associated with liver damage.

**Clinical Pearl / High-Yield Fact**
When starting DMARDs, it's essential to obtain a baseline LFT and to monitor liver function regularly, especially with medications like Leflunomide and Sulfasalazine. This can help identify potential hepatotoxicity early, preventing liver damage and its consequences.

**Correct Answer: B. Sulfasalazine.**