An instructor is conducting a virtual classroom with an international audience and finds that any single method used for delivery of the material leaves about a third of the learners uninvolved. Which of the following is the BEST course of action? 

Answer options:

A. Send out a public message to the class asking which method of delivery is working best for the class
B. Send out a private message to each learner asking which method of delivery is working best for them
C. Query for commonalities amongst the learners,
D. Continue to use multiple means of delivery

D