Many people are aware that high cholesterol contributes to heart disease, but they will be surprised to learn that cholesterol performs essential functions in the human body. A lipid made in the liver and found in animal cell membranes, cholesterol is used to repair tissues and digest fat, as well as in the manufacture of hormones, bile salts, and Vitamin D. However, problems arise when an excess of cholesterol builds up on blood vessel walls, thus impeding blood flow. A persons blood cholesterol count is comprised of two different types of cholesterol: low-density lipoprotein (LDL), sometimes called bad cholesterol, and high-density lipoprotein (HDL), known as good cholesterol. Whereas HDL carries cholesterol away from the arteries to the liver, LDL carries cholesterol from the liver to the arteries where it accumulates. Although certain foods deriving from animals, such as meat, shellfish, cheese and eggs, are high in dietary cholesterol, it is actually the consumption of the saturated fats found in red meat, full-fat dairy products, cakes and biscuits that raises levels of bad cholesterol. Conversely, eating polyunsaturated fats and soluble fibre can lower LDL.

Question: Making dietary changes is the only way to lower bad cholesterol levels.
Options:
A. true, B. false, C. uncertain
Answer: "C"