What distinguishes a heart attack from heart failure.

a. a heart attack results from poor blood flow, while heart failure involves a total interruption of blood flow.

b. both heart attack and heart failure result in heart tissue death, but more tissue dies as a result of heart failure.

c. heart tissue dies during a heart attack, while heart failure results in systemic oxygen deficiency.

d. heart failure results in body tissues receiving such a high level of oxygen that it is toxic.