Which of the Following Statements Is Correct for Vitamin Supplements

Which of the following statements is correct for vitamin supplements?

A) A megadose is generally defined as an amount ten times the RDA, although it is sometimes lower for certain vitamins
B) Vitamin/mineral overdoses result in about 1,000 fatalities in the United States each year
C) You should buy supplements containing 200 percent of the RDA for all vitamins and minerals
D) National brands of supplements are more expensive, but have less impurities, thus, they are a more prudent choice