**Core Concept**
Vitiligo is an autoimmune skin condition characterized by the loss of pigment-producing melanocytes, leading to white patches on the skin. It is often associated with other autoimmune disorders due to shared genetic and environmental risk factors.

**Why the Correct Answer is Right**
Vitiligo is commonly linked with autoimmune disorders such as Hashimoto's thyroiditis, type 1 diabetes, and multiple sclerosis. This association is thought to be due to the presence of autoantibodies and genetic predisposition. In particular, the HLA-DR4 and HLA-DR5 alleles have been associated with an increased risk of developing vitiligo and other autoimmune diseases.

**Why Each Wrong Option is Incorrect**
**Option A:** Rheumatoid arthritis - This is incorrect because rheumatoid arthritis is not typically associated with vitiligo. While both conditions are autoimmune, they have different underlying pathophysiologies and are not commonly seen together.

**Option B:** Alopecia areata - This is incorrect because alopecia areata, an autoimmune condition characterized by hair loss, is actually linked with vitiligo in some studies. The two conditions may share a common underlying autoimmune mechanism.

**Option C:** Graves' disease - This is incorrect because Graves' disease, an autoimmune condition that causes hyperthyroidism, is not typically associated with vitiligo. However, it is worth noting that some studies have suggested a possible link between Graves' disease and vitiligo.

**Option D:** Psoriasis - This is incorrect because psoriasis, a chronic autoimmune skin condition characterized by thick, scaly skin patches, is not typically associated with vitiligo. While both conditions are autoimmune, they have different underlying pathophysiologies and are not commonly seen together.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that vitiligo can be a marker for underlying autoimmune disease, particularly when it appears in conjunction with other autoimmune symptoms or laboratory abnormalities.

**Correct Answer: A. Rheumatoid arthritis**