What type of organic compounds are primarily composed of carbon and hydrogen and serve as a source of stored energy?

The correct choice is lipids, which are organic compounds primarily made up of carbon and hydrogen. They are known for their ability to store energy efficiently. Lipids include fats, oils, and waxes, and they can store more energy per gram compared to carbohydrates. This high energy content makes them a crucial source of stored energy for organisms.

In addition to providing energy, lipids also play roles in cell structure, as they are major components of cell membranes, and are involved in signaling processes within biological systems. Hence, lipids are essential for both energy storage and various physiological functions in living organisms.

Other options, such as carbohydrates, do also serve as energy sources but are structured differently and hold less energy per gram compared to lipids. Proteins are primarily involved in building and repairing tissues rather than serving as a main energy source. Nucleic acids, like DNA and RNA, play critical roles in the storage and transmission of genetic information and are not primarily energy sources. Thus, lipids are the best choice when discussing organic compounds that provide stored energy.