According to the passage, which of the following is TRUE?
A.
When athletes take steroid creams, they would be definitely tested.
B.
The testing system is not exact enough because the athletes are informed testing schedules beforehand.
C.
More than half of the Olympic—caliber U.S. athletes have taken the dreadful drugs to win the game
D.
Erythropoietin is a kind of drug that can enhance an athlete's performance in 20 minutes.