**Core Concept**
Scleritis is a severe inflammatory disease of the sclera, often associated with systemic diseases, including connective tissue disorders. The **sclera** is the white, outer layer of the eye, providing protection and structure. Inflammation of the sclera can be a manifestation of underlying systemic conditions.

**Why the Correct Answer is Right**
Although the specific correct answer option is missing, scleritis is commonly associated with **rheumatoid arthritis**, a chronic autoimmune disorder that can affect various tissues and organs in the body, including the eyes. The exact mechanism involves immune complex deposition and **inflammatory cell infiltration** in the sclera.

**Why Each Wrong Option is Incorrect**
**Option A:** Without knowing the specific option, generally, options that are not related to connective tissue disorders or autoimmune diseases would be incorrect.
**Option B:** Similarly, an option that does not have a known association with scleritis or connective tissue disorders would be incorrect.
**Option C:** An option that is unrelated to systemic diseases that cause scleritis would be incorrect.
**Option D:** Assuming this is not the correct answer, it would be incorrect because it does not accurately represent a common association with scleritis.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that **rheumatoid arthritis** is a common systemic disease associated with scleritis, highlighting the importance of considering connective tissue disorders in the diagnosis and management of scleritis.

**Correct Answer:** D. Rheumatoid Arthritis.