Controlling the position of your body while in a static or dynamic position is what

Ibelieve it's choice d.

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.

Ican only answer your first question, a machine is like a human body because it's a little similar. they both almost work like the same.