The myocardium receives its blood supply from the coronary arteries.

The coronary arteries provide the main blood supply to the heart. The coronary arteries also supply the myocardium with oxygen to allow for the contraction of the heart and thus causing circulation of the blood throughout the body.

Explanation:

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i believe the correct answer from the choices listed above is the first option. the scientists need to look at the   validity of data, claims, hypotheses, and observations before  developing an argument. they base their arguments on facts that are present and they make sure they have proofs. 

explanation:

answer; atp and nadph;