Answer:
(a) Non verbal communication
Explanation:
Analysing the given options
(a) Non-Verbal Communication: This involves the use of signs and expressions other than words for communication
(b) Oral Communication: This basically means spoken words
(c) Verbal communication: This is another expression that represents (b) oral type of communication
(d) Written communication: Literally, this includes writing down words for communication
After analysing (a) to (d), we can conclude that (a) answers the question.
