In a conversation with himself, malik says, "i think, therefore i am." what type of communication is malik engaged in?

The answer is b) Intrapersonal communication

Intrapersonal is defined as something that takes place within our own mind. Hence, intrapersonal communication is when we 'talk to ourselves' when trying to make a decision.

These can be thoughts and actually take form of a language. Hence, every person 'thinks' and 'talk to themselves' in their own native language. 

Many believe that this ability, to think and talk to ourselves is a major ''human experience of the consciousness''