A person with a type B lipid profile is at much greater risk of heart disease than a person with a type A lipid profile. In an experiment, both type A volunteers and type B volunteers were put on a low-fat diet. The cholesterol levels of the type B volunteers soon dropped substantially, although their lipid profiles were unchanged. The type A volunteers, however, showed no benefit from the diet, and 40 percent of them actually shifted to type B profiles. If the information above is true, which one of the following must also be true?
A: The reduction in cholesterol levels in the volunteers is solely responsible for the change in their lipid profiles.
B: Apart from adopting the low-fat diet, most of the volunteers did not substantially change any aspect of their lifestyle that would have affected their cholesterol levels or lipid profiles.
C: For at least some of the volunteers in the experiment, the risk of heart disease increased after having been put on the low-fat diet.
D: In the experiment, most of the volunteers had their risk of heart disease reduced at least marginally as a result of having been put on the diet.
Choose A, B, C or D as your solution.
C