"C. After 15 minutes" would be an appropriate time to suggest a client begin to monitor his or her pulse after beginning an exercise, since this gives enough time for the heart to become acclimated with the new pace.
C. a general hired to train foreign troops
"It represented a major setback for the federal government due to public suspicion."
Obviously Watergate was huge and it had the public worrying that they could not trust their government anymore.