An ocean scientist plans to spend several days underwater in a submarine. Doctors on land will monitor her body to make sure she is healthy during her trip. What is one way doctors will be able to tell whether her body is healthy enough to do all her tasks while she is in the submarine? A. The doctors could see if her cells are getting several different types of food molecules.

B. The doctors could see if she is getting plenty of sleep so her body can make enough energy.

C. The doctors could see if her lung cells have molecules from air, and her stomach cells have molecules from food.

D. The doctors could see if her cells are getting the molecules they need from food and air.