**Core Concept**
The question is testing knowledge of newer pharmacological treatments for Rheumatoid Arthritis (RA), specifically oral medications. This requires understanding of the evolving landscape of RA management, including biologic agents and small molecule inhibitors.

**Why the Correct Answer is Right**
The correct answer is likely a Janus Kinase (JAK) inhibitor, such as Tofacitinib or Baricitinib. These oral medications work by selectively inhibiting JAK enzymes, which play a crucial role in the signaling of various cytokines involved in the inflammatory process of RA. By blocking these enzymes, JAK inhibitors reduce inflammation and slow joint damage. Tofacitinib and Baricitinib have been approved for the treatment of moderate to severe RA, offering patients an alternative to traditional disease-modifying antirheumatic drugs (DMARDs) and biologic agents.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is likely a biologic agent, such as Tumor Necrosis Factor-alpha (TNF-alpha) inhibitors (e.g., Adalimumab, Infliximab). While effective, biologics are administered via injection, making this option incorrect.
* **Option B:** This option might be a traditional DMARD, such as Methotrexate or Hydroxychloroquine. While these medications are cornerstone treatments for RA, the question specifically asks for a "new oral drug," making this option incorrect.
* **Option D:** This option could be a non-steroidal anti-inflammatory drug (NSAID), such as Ibuprofen or Naproxen. NSAIDs are used to manage RA symptoms but are not considered disease-modifying agents, making this option incorrect.

**Clinical Pearl / High-Yield Fact**
When considering treatment options for RA, it's essential to remember that JAK inhibitors offer a unique mechanism of action, distinct from biologics and traditional DMARDs. This allows for more flexibility in treatment regimens and may provide benefits for patients who have not responded to other therapies.

**Correct Answer: C. Tofacitinib.**