**Core Concept**
Hydralazine is a direct vasodilator that acts on the smooth muscle of the blood vessels to cause a decrease in peripheral resistance. Prolonged use of hydralazine can lead to a condition known as a lupus-like syndrome, characterized by the development of autoantibodies and immune complex deposition.

**Why the Correct Answer is Right**
The mechanism of hydralazine-induced lupus-like syndrome involves the formation of hydralazine metabolites that act as haptens, binding to self-antigens and triggering an immune response. This leads to the production of autoantibodies, particularly anti-histone antibodies, and the deposition of immune complexes in various tissues. The pathophysiology of this condition is thought to involve the activation of T cells and the production of cytokines, leading to inflammation and tissue damage.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because hydralazine-induced lupus-like syndrome is not primarily associated with the development of thrombocytopenia.
**Option B:** This option is incorrect because while hydralazine can cause tachycardia as a side effect, it is not the most likely cause of a lupus-like syndrome.
**Option C:** This option is incorrect because hydralazine-induced lupus-like syndrome is not primarily associated with the development of nephrotic syndrome.

**Clinical Pearl / High-Yield Fact**
Hydralazine-induced lupus-like syndrome is a well-documented side effect of prolonged hydralazine use, and it is essential to monitor patients for signs of autoimmunity, such as the development of anti-histone antibodies, when using this medication.

**Correct Answer:** D.