Cardiac muscle cells have a tremendous demand for oxygen in order for their mitochondria to break down enough fatty acids and glucose for energy. Where do cardiac muscle cells get all of the oxygen that they need
a. from the oxygen stored in the myoglobin molecules found in the cardiac muscle cells
b. from the oxygen stored in the hemoglobin molecules found in cardiac muscle cells
c. from the oxygen available in the coronary circulation
d. from the oxygen available in both the coronary circulation and stored in the myoglobin molecules found in the cardiac muscle cell