Final answer:
Vitamin C is the vitamin that is neither fat nor water-soluble.
Step-by-step explanation:
The vitamin that is neither fat nor water-soluble is vitamin C.
According to the information provided, vitamins can be divided into two categories: fat-soluble vitamins, which include vitamins A, D, E, and K, and water-soluble vitamins, which include the B complex vitamins and vitamin C. Water-soluble vitamins contain large numbers of electronegative oxygen and nitrogen atoms, which can engage in hydrogen bonding with water. Vitamin C, also known as ascorbic acid, falls into this category.