Which of the following is a primary role of carbohydrates in the body?

Carbohydrates serve a primary role in the body by providing energy. They are one of the three macronutrients, alongside proteins and fats, and are the body's main source of fuel. When carbohydrates are consumed, they are broken down into glucose, which is then utilized by the body's cells for energy. This energy is essential for various bodily functions, including physical activity, brain function, and maintaining homeostasis.

While other nutrients and processes are certainly important in the body, carbohydrates’ direct contribution to energy metabolism is what makes this choice the most accurate. Reducing cholesterol levels, supporting immune function, and facilitating hormone production are roles primarily associated with other nutrients, such as fats, proteins, and vitamins, rather than carbohydrates. Thus, the primary function of carbohydrates is effectively captured by the option that emphasizes their energy-providing capability.