The body can store large amounts of a) vitamin B-12. b) thiamin. c) vitamin C. d) riboflavin.

The correct answer is (a) vitamin B-12. The body can store large amounts of vitamin B-12 in the liver, which can last for several years. This is because vitamin B-12 is a water-soluble vitamin, meaning it dissolves in water and can be stored in the body's tissues. In contrast, thiamin, vitamin C, and riboflavin are all water-soluble vitamins that cannot be stored in large amounts, so they must be consumed regularly through the diet or with supplements.