Answer:
Adapt.
Step-by-step explanation:
According to the theory of "Transactional Model of Communication", communication is not just only a mode of transmitting and interacting our ideas with others in the society, but it is a mode in which communication helps not only to express but also to adapt.
In this model of communication, the sender and receivers are called communicators. The communicators in this model of communication, communicate or share messages. The messages that they share help them to adapt their communication.
So, the correct answer is adaptation in communicators makes communication more effective.