which of the following is the main function of vitamins?

A.provinding structure to cell membrane
B.supplying brain with energy source
c.Facilitating action of enzymes
D.Promoting absorption of carbohydrates

http://www.livestrong.com/article/246782-what-is-the-general-function-of-vitamins/

The main function of vitamins is to facilitate the action of enzymes (option C). Vitamins play a crucial role in the body's metabolic processes by acting as coenzymes or cofactors. While vitamins themselves do not provide energy directly or provide structure to cell membranes, they are essential for the proper functioning of various enzymes that are involved in energy production, macronutrient metabolism, and maintaining overall physiological health.

To arrive at this answer, I used my knowledge base to understand the functions of vitamins and their role in the body. This information can also be easily found in nutrition textbooks, scientific journals, and reliable online sources. It is important to consult trusted sources when researching and verifying information.