**Core Concept**
Dyslipidemia in the context of antiretroviral therapy (ART) refers to the alteration of lipid profiles, leading to increased risk of cardiovascular disease. This side effect is associated with certain classes of antiretroviral drugs, particularly those targeting the human immunodeficiency virus (HIV) reverse transcriptase and protease enzymes.

**Why the Correct Answer is Right**
Antiretroviral drugs can induce dyslipidemia through various mechanisms, including:
- **Metabolic alterations**: Some antiretrovirals disrupt lipid metabolism, leading to increased triglycerides, LDL cholesterol, and decreased HDL cholesterol.
- **Hormonal changes**: Certain antiretrovirals can affect hormone levels, including cortisol, insulin, and growth hormone, contributing to dyslipidemia.
- **Mitochondrial toxicity**: Some antiretrovirals can impair mitochondrial function, leading to increased lipid synthesis and accumulation.

**Why Each Wrong Option is Incorrect**
* **Option A:** Didanosine, a nucleoside reverse transcriptase inhibitor (NRTI), is known to cause dyslipidemia.
* **Option B:** Ritonavir, a protease inhibitor (PI), is associated with dyslipidemia due to its metabolic effects.
* **Option D:** Efavirenz, a non-nucleoside reverse transcriptase inhibitor (NNRTI), can cause dyslipidemia, although the mechanism is less well understood.

**Clinical Pearl / High-Yield Fact**
When initiating antiretroviral therapy, monitoring of lipid profiles is essential to identify patients at risk of dyslipidemia and to adjust treatment accordingly.

**Correct Answer:** A. Didanosine.