The correct option is B ECG
Myocardial infarction commonly known as a heart attack, occurs when blood stops flowing properly to a part of the heart, and the heart muscle is injured because it is not receiving enough oxygen. The main ways to determine if a person has had a myocardial infarction are electrocardiograms (ECGs) that trace the electrical signals in the heart and testing the blood for substances associated with damage to the heart muscle.