How are macromolecules related to energy?

Explanation:

While carbohydrates supply immediate energy for the body, lipids — a class of macromolecule — provide long-term energy storage. Lipids, more commonly known as fats, appear in many foods. There are dozens of lipids, many of which are important for living things.

i think it would be b. tissue because an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.