Charles is an engineer who is evaluating a prototype of an artificial heart. The prototype beats in a synchronized fashion, is hollow, and has tubes attached to it. It can be powered by electrical signals from the brain when it is interfaced with the appropriate nerves. What important feature should Charles notice the prototype is missing? blood vessels to transport blood a structure that would divide the hollow heart into chambers to separate oxygenated blood from deoxygenated blood a blood filtering mechanism to separate oxygenated blood from deoxygenated blood a structure to pump blood through the valves