If a change in the body causes more change, but in the opposite direction the system is called
a. feedback inhibition.
b. positive feedback.
c. negative feedback.
d. neutral feedback.

It's a positive feedback system. An example is childbirth, where the cervical opening gets increasingly larger to accomodate the impending birth.

Well, l think that some effective communication is, emotional barriers and lack of attention, interest distraction or irrelevance. also some physical disabilities such as hearing problems or speech difficulties.      l hope i am correct  and you good luck.