The cardiovascular system compose of baroreceptors, chemoreceptors etc to maintain constant blood pressure. Blood pressure is the ration of systolic pressure to diastolic pressure. In the above case, primary purpose of information given by writer is to inform reader the way cardiovascular system is regulated by these above receptors, renal systems.
In normal arteries, according to the speed and volume of the blood, the diameter of the blood vessel changes accordingly and optimum peripheral resistance is maintained which is essential for proper flow of blood.
Thus, the options (d), (a) and (b) are incorrect.
Blood pressure is the ration of systolic pressure to diastolic pressure. In the above case, primary purpose of information given by writer is to inform reader the way cardiovascular system is regulated by these above receptors, renal systems.
Therefore, the correct option is – c. To inform the reader how the cardiovascular system regulates blood pressure.