**Core Concept**
The question tests the student's knowledge of lipid-lowering drugs and their effects on lipoprotein(a) [Lp(a)] levels. Lipoprotein(a) is a type of lipoprotein that carries cholesterol in the blood and is associated with an increased risk of cardiovascular disease. Certain medications can lower Lp(a) levels, which may help reduce this risk.

**Why the Correct Answer is Right**
Niacin, also known as nicotinic acid, is a lipid-lowering medication that has been shown to significantly reduce Lp(a) levels. This effect is thought to be due to niacin's ability to inhibit the release of very-low-density lipoprotein (VLDL) from the liver, which in turn reduces the levels of Lp(a) in the blood. Niacin also has a number of other beneficial effects on lipid metabolism, including increasing high-density lipoprotein (HDL) cholesterol and reducing triglyceride levels.

**Why Each Wrong Option is Incorrect**
* **Option A:** Statins are a class of lipid-lowering medications that work by inhibiting the enzyme HMG-CoA reductase, which is involved in the production of cholesterol in the liver. While statins are effective at lowering LDL cholesterol, they do not have a significant effect on Lp(a) levels.
* **Option B:** Fibric acid derivatives, such as fenofibrate, are lipid-lowering medications that work by activating peroxisome proliferator-activated receptor-alpha (PPAR-alpha), which regulates the expression of genes involved in lipid metabolism. While fibric acid derivatives can lower triglyceride levels and increase HDL cholesterol, they do not have a significant effect on Lp(a) levels.
* **Option C:** Bile acid sequestrants, such as cholestyramine, are lipid-lowering medications that work by binding to bile acids in the gut and preventing their reabsorption. This leads to an increase in the conversion of cholesterol to bile acids in the liver, which in turn reduces the levels of LDL cholesterol. However, bile acid sequestrants do not have a significant effect on Lp(a) levels.

**Clinical Pearl / High-Yield Fact**
Niacin is a unique lipid-lowering medication that can lower Lp(a) levels, in addition to its effects on LDL cholesterol, HDL cholesterol, and triglycerides. This makes it a useful option for patients with high Lp(a) levels and a history of cardiovascular disease.

**Correct Answer:** C. Niacin is a lipid-lowering medication that significantly reduces Lp(a) levels.