What is the role of oxygen in the body?

The role of oxygen in the body primarily centers around its function in cellular respiration, a vital process by which cells convert food into usable energy. During this process, oxygen is utilized to help break down glucose and other nutrients, allowing cells to produce adenosine triphosphate (ATP), which serves as the primary energy currency of the cell. This energy is crucial for powering many bodily functions, including muscle contraction, brain activity, and maintaining homeostasis.

While there are other processes in the body that involve oxygen, such as the expulsion of carbon dioxide and supporting efficient blood circulation, these roles do not encapsulate the primary function of oxygen. Instead, they are more about maintaining balance in the body after oxygen has fulfilled its main role in energy production. Thus, oxygen’s most significant and direct role is to aid in the breakdown of food into energy, making option B the correct choice.