Answer:
a. Make your listeners care
Step-by-step explanation:
Effective listening: The term effective listening is defined as a process of actively grasping a piece of information given to an individual through a speaker, displaying that he or she is interested and listening and therefore proving a feedback (asking questions) to the speaker to make him or her understand or realize that the message or the information was being received.
Effective listening is a form of skills that encompass various positive human relationships.
In the question above, the techniques used by Colin is to make your listeners care.