Hint: The heart is a muscular organ in the human body, it is about the size of a fist. In our body it is located at the left of the breast bone, the heart has a major role in our body as through the arteries and veins it pumps the blood to all the organs and the system is known as the cardiovascular system.
Complete answer: Let us study the options to find the correct answer: Option A: there are four chambers of the heart and the right ventricle is the interior one among all as the main function of the right ventricle is that from the right atrium, it receives the deoxygenated blood and pumps it into the pulmonary circulation. Therefore, this is an incorrect answer.
Option B: out of the four chambers, the left auricle is located at the left posterior side of the heart. Its main function is to hold the blood that is returning from the lungs in its chamber and pumps the blood to the other areas of the heart. Therefore, this is an incorrect answer.
Option C: the right auricle is a small conical pouch and a muscular organ and it is the first part of the heart which receives the deoxygenated blood. Its main function is that after receiving deoxygenated blood directs it to the right ventricle. Therefore, this is the correct answer.
Option D: out of the four chambers of the heart it is the thickest one. Its main function is that it pumps the oxygenated blood to the tissues all over the body. Therefore, this is an incorrect answer.
Note: In the heart, there is a septum that is the central wall of the heart that separates the left and right auricle and left and right ventricle from each other. The various factors affecting heart rate are, i) During anxiety the heart increases ii) Age iii) Medications iv) Diet and fitness levels