Which of the following is called vitamin H?A.BiotinB.Folic acidC.ThiamineD.Niacin

The correct answer is A. Biotin.

Explanation:
Vitamin H is another name for Biotin, which is a water-soluble B-vitamin (specifically B7). It plays a crucial role in several metabolic processes, including the metabolism of carbohydrates, fats, and proteins. Biotin is essential for maintaining healthy hair, skin, and nails, and it also contributes to the proper functioning of the nervous system.

The other options are different vitamins:

B. Folic acid (Vitamin B9) is important for DNA synthesis and repair, as well as cell division and growth.
C. Thiamine (Vitamin B1) is essential for carbohydrate metabolism and plays a role in nerve, muscle, and heart function.
D. Niacin (Vitamin B3) is involved in energy production and the metabolism of fats, carbohydrates, and proteins.
Thus, the vitamin commonly referred to as Vitamin H is Biotin.