An instructor is teaching a virtual class and notices that learner interaction has begun to taper off. A break was recently taken so fatigue does not seem to be the issue, but rather a lack of understanding. Which of the following should the instructor implement to help identify where learners are getting confused"? 

Answer options:

A. Switching from lecture to a more visual training method.
B. Quiz the learners during the virtual session.
C. Conduct a quick review session.
D. Introduce supporting materials.

B