**Core Concept**
Antinuclear antibodies (ANAs) are a group of autoantibodies directed against the cell nucleus, which play a crucial role in the diagnosis of autoimmune diseases such as Systemic Lupus Erythematosus (SLE). The presence of ANAs in a patient's serum can indicate an underlying autoimmune process.

**Why the Correct Answer is Right**
The correct answer is the ANA specific for SLE. The most commonly used ANA test is the fluorescent antinuclear antibody (FANA) test, which detects a wide range of autoantibodies. However, the ANA specific for SLE is the Sm (Smith) antibody, which is a type of autoantibody that targets specific proteins within the cell nucleus. The Sm antibody is highly specific for SLE and is often used as a diagnostic marker for the disease.

**Why Each Wrong Option is Incorrect**
* **Option A:** Anti-Ro and anti-La antibodies are associated with Sjögren's syndrome and SLE, but they are not specific for SLE.
* **Option B:** Anti-SSB/La antibodies are associated with Sjögren's syndrome and SLE, but they are not specific for SLE.
* **Option D:** Anti-CCP antibodies are specific for rheumatoid arthritis, not SLE.

**Clinical Pearl / High-Yield Fact**
Remember that the Sm antibody is highly specific for SLE, but it is not sensitive. This means that while the Sm antibody can confirm a diagnosis of SLE, its absence does not rule out the disease.

**Correct Answer: A. Sm (Smith) antibody**