Which of the Following Characterizes Niacin's Utility in Improving Blood

Which of the following characterizes niacin's utility in improving blood cholesterol levels?

A) It is safe enough to be taken without medical supervision because it is a vitamin.
B) It is valuable if used properly, although it can irritate the liver and cause flushing of the skin.
C) It is one of the most expensive cholesterol-lowering drugs.
D) It is effective enough that people with high cholesterol who take it don't have to worry about how much fat they consume.
E) It has not been proved effective.