I honestly do not understand what answer A or B means but answers C and D could both be acceptable depending on the situation. Body language is important in most situations, excluding letters, phone, texting, ECT. A person's body language can communicate to someone that they are being sincere or not, shows that they are confident in what you are saying, or if they are a friendly and trustworthy person or not. An example would be if the person is talking to you and they keep shifting around, you would be subconsciously be thinking that the person is either uncomfortable or is hiding something. If they smiled and looked you in the eyes you would be more willing to trust them. If only one answer had to be chosen, this would be the one.
Planning, while less important than the last, is still important. If you are going to be giving a presentation or you have a meeting coming up, preparation and planning is important. Besides planning what would be talked about and what your side of the story would be, there also needs to be preparation on how you would present the information. How you present not only helps to get your point across and make you sound "smarter," but also shows that you are not trying to offending those you are presenting to. If you are in a meeting you need to think of the ranks of those who will be there. You would not talk down to your boss as if they have no idea what you are talking about, while more explanation and an assertion of rank would be needed if you are discussing things with those who work for you. If you are meeting with someone from another country, you would need to study their customs and manners as to not offend them.