What role do B vitamins play in the body?

B vitamins play a crucial role in various metabolic processes in the body, particularly in energy metabolism and the production of red blood cells. They are involved in converting carbohydrates, fats, and proteins into energy, thereby supporting the body's energy needs. Additionally, certain B vitamins, such as B12 and folate, are essential for the synthesis of red blood cells, which is vital for maintaining proper oxygen transport throughout the body.

Each of the other options highlights important functions of different nutrients or vitamins but does not accurately represent the primary roles of B vitamins. For instance, while bone health can be influenced by certain nutrients such as vitamin D and calcium, it does not fall under the purview of B vitamins. Similarly, the primary responsibility for vision lies with vitamins A and other antioxidants, rather than B vitamins. Lastly, skin health is often associated with vitamins such as vitamin E and vitamin C, not specifically B vitamins. Thus, option C correctly encapsulates the essential functions that B vitamins serve in energy metabolism and the production of red blood cells.