Answer:
The correct answer is C. Breath
Explanation:
Lungs and heart are responsible for the proper breathing and both are situated in the thoracic cavity. A proper function of the lungs requires the proper function of the heart and proper functioning of the heart requires the proper functioning of the lungs.
Therefore if the heart is not strong enough then it will be difficult to breathe because the heart pumps the oxygenated blood to the tissues and deoxygenated blood is pumped to the lungs so that the CO₂ can be exhaled. This is the reason that in heart failure people feel breath shortage.
Therefore the right answer is C. Breath.
