Read this line from the text:

Later the dog will learn more difficult tasks: to pick up a scent from an article of clothing or pick out a particular human scent in a crowd of people, for example. Which of the following is likely a strategy used to teach SAR dogs these more difficult tasks?

APlaying focused games, such as finding a toy containing a treat
BLearning games, few of which relate to search and rescue
CRepeating drills like sitting, heeling, and staying
DWatching other dogs, mainly to give the trainee some rest