#1, they remain outside the target cell. #2, bind to the receptors inside the target cell. #3, they have no target cells. #4, are made of proteins.
I'm not entirerly sure whether ANY of these statements could be considered untrue.
Socializing up to a certain extent could increase productivity, granted it would be done with work in mind.
B, C, D all are true as these are very commonplace things that can happen at the workplace, while not all are equally probable all of them could happen.
If one really is considered untrue, it most likely would be A.
I think c would be the answer
