Which of these might be an example of an advertiser's target group? A. People who watch a variety of TV shows
B. People the advertiser knows nothing about
c. People who have no access to media
D. People who live in the same region of the country

I believe the answer would be A ^^

an advertiser would have more accessibility to a group of people who watch TV often

the following key ideas correctly express the key sentence.

restate key idea: most people can learn to swim in ten short lessons.

restate key idea: the majority of water-accident victims require mouth-to-mouth breathing.

restate key idea: an empty, tightly closed gallon jug will support a tired swimmer.  

restate key idea: first aid is to prevent accidents as well as assist in rescue.

explanation: the key idea needs to have the same topic as the key sentence (drowning and safety).

he uses the metaphor autumn.