In general, which is not critical to understanding how to communicate effectively?

In general, which is NOT critical to understanding how to communicate effectively?
A. active listening
B. verbal and nonverbal communication
C. communicating 4 to 5 times per day
D. communication styles

Ans:
Communicating 4 to 5 times per day is NOT critical to understanding how to communicate effectively.

In general, which is not critical to understanding how to communicate effectively?