A weight lifter passes out in the gym and is taken to the local hospital. The doctor discovers that she is in shock and also has an enlarged heart. What type of supplement would the doctor consider to be the most likely cause of the problem?

A. a muscle-building supplement like a growth hormone
B. an endurance-enhancing supplement like caffeine
C. a muscle-building supplement like anabolic steroids
D. an endurance-enhancing supplement like erythropoietin