I think the correct answer should be asking questions because its the best way she attracts the group into participating. If she refers to the agenda, a handful of people will actually listen to her. If she reviews or summarizes her notes may be helpful but not the best idea. And if she uses body language, she may get a few people listening. Asking questions make sure that the individual is learning the content. And if you ask a question to an individual who isn't participating then, he or she will get embarrassesd, which will make sure the other participants pay attention.
