**Rheumatoid Arthritis Core Concept**
Rheumatoid arthritis (RA) is a chronic autoimmune disorder characterized by inflammation of the synovial joints, leading to cartilage and bone destruction. The pathogenesis of RA involves a complex interplay between genetic predisposition, environmental factors, and immune system dysregulation.

**Why the Correct Answer is Right**
RA is associated with the production of autoantibodies, particularly rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPAs), which play a crucial role in the disease's pathogenesis. The synovial lining of the joints becomes hyperplastic, leading to the production of pro-inflammatory cytokines such as TNF-alpha, IL-1, and IL-6, which contribute to joint inflammation and destruction. The disease process is also characterized by the activation of various immune cells, including T cells, B cells, and macrophages.

**Why Each Wrong Option is Incorrect**
**Option A:** This statement is not true. RA is indeed a systemic disease, but it primarily affects the joints, particularly the hands and feet.
**Option B:** This statement is not true. RA is characterized by the presence of autoantibodies, including RF and ACPAs, which are used as diagnostic markers.
**Option C:** This statement is not true. RA is a chronic autoimmune disorder, not a self-limiting condition.

**Clinical Pearl / High-Yield Fact**
RA is more common in women than men, with a female-to-male ratio of approximately 3:1. The disease typically presents in middle age, with a peak incidence between 30 and 60 years of age.

**Correct Answer: A. RA is primarily a joint disease.**