**Core Concept**
The regulation of cholesterol synthesis is a complex process involving multiple enzymes, transcription factors, and regulatory pathways. It is crucial for maintaining cholesterol homeostasis and preventing the accumulation of toxic intermediates.

**Why the Correct Answer is Right**
Cholesterol synthesis is primarily regulated by the transcription factor SREBP-2 (Sterol Regulatory Element Binding Protein 2) and SREBP-1c, which are activated in response to low cholesterol levels. The rate-limiting enzyme of cholesterol synthesis is HMG-CoA reductase, which is also regulated by feedback inhibition by cholesterol and other intermediates. Additionally, the nuclear receptor LXR (Liver X Receptor) promotes cholesterol efflux and inhibits cholesterol synthesis.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because HMG-CoA reductase is indeed the rate-limiting enzyme of cholesterol synthesis, making this statement true.
**Option B:** Incorrect because SREBP-2 is indeed involved in the regulation of cholesterol synthesis, making this statement true.
**Option C:** Incorrect because the statement is too vague, but the regulation of cholesterol synthesis is indeed influenced by various factors, including dietary cholesterol intake and genetic mutations.

**Clinical Pearl / High-Yield Fact**
It is essential to note that dysregulation of cholesterol synthesis can lead to various diseases, including familial hypercholesterolemia (FH) and sitosterolemia. SREBP-2 and SREBP-1c are also involved in the regulation of fatty acid synthesis.

**Correct Answer: D.**