Among the following, which is a function of riboflavin?

Riboflavin, also known as vitamin B2, plays a critical role in energy production through its involvement in the metabolism of carbohydrates, fats, and proteins. It is a key component of the coenzymes flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), which are essential for various oxidative reactions in the body. These coenzymes are pivotal in the electron transport chain, a major energy-producing pathway, where they help facilitate the conversion of macronutrients into adenosine triphosphate (ATP), the primary energy currency of cells. Therefore, the function of riboflavin in energy production is fundamental for maintaining overall metabolic health and efficiency.

The other functions listed—production of proteins, supporting immune function, and synthesis of fatty acids—are more associated with different vitamins and nutrients. While riboflavin supports some cellular processes that may indirectly affect these functions, its primary role is specifically centered around energy metabolism.