Which of the Following Is True of Niacin

Which of the following is true of niacin? 

A)  Large doses of the nicotinic acid form can raise HDL cholesterol. 
B)  Large doses of the nicotinic acid form can raise LDL cholesterol. 
C)  Treatment for the deficiency disease, pellagra, often includes supplements of the amino acid leucine. 
D)  Toxicity is unknown. 
E)  High doses can treat liver diseases.