Answer:
Myocardium.
Step-by-step explanation:
Myocardial infarction may be defined as the medical condition when the flow of blood stops or decrease and not supplied to the heart. This condition is also known as heart attack.
Heart acts as the main pumping organ of the body. During the myocardial infarction, this pumping activity of the heart gets damage. This damage occurs in the main heart layer known as myocardium as it is mainly responsible for the heart pumping.
Thus, the correct answer is option (C).