Heart Muscle Is Damaged After a Heart Attack (MI) Because

Heart muscle is damaged after a heart attack (MI) because blood flow to the heart is stopped. A researcher injected cyanobacteria into the damaged hearts of test animals that has been given MIs. The animals' conditions improved after the procedure, but not significantly. The researcher repeated the experiment, this time illuminating the cyanobacteria with high intensity light after injecting the cells into the damaged hearts. Now the animals did much better, recovering well from their heart attacks. Which of the following explains this outcome?

A) Cyanobacteria have the capacity to carry blood. Illuminating the cells increases their ability to transport blood into the damage heart muscle.
B) Cyanobacteria produce alcohol through photosynthesis, and this stimulates the heart cells. Illuminating the bacteria increases this reaction.
C) Illuminated cyanobacteria multiply rapidly; the expanding mass of cells dilates blood vessels to the heart, bringing more nutrients and oxygen to the heart cells.
D) Illuminated cyanobacteria produce carbon dioxide by photosynthesis. Illumination increases the amount of released CO₂ that the heart cells then use for anaerobic respiration.
E) Cyanobacteria produce oxygen by photosynthesis. Illuminating the cells increases amount of O₂ released that is then used by heart cells for aerobic respiration.