The cardio-respiratory system consists of the cardio vascular system (heart and blood vessels) together with respiratory system (lungs and air ways). These systems work to transport oxygen to the muscles and organs of the body and remove waste products including carbon dioxide.
e. decision making because a means that you have not reached a conclusion, be is more of "i only have so much" type of answer, c does not make sense, and definitely not d.
The Epiglottis protects food from entering the larynx.
