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 would say C, schizophrenia,
because schizophrenia is "a mental disorder that in many ways centers around not recognizing what is part of reality – namely, having psychotic breakdowns." It is not related to anxiety, as anxiety is classified as "neurotic" while schizophrenia is classified as "psychotic".
A possible response of doing a zero tolerance action is ISS(In school Suspension), suspension, or getting expelled.
A chromosome contains many genes that encode for proteins. .... a change to the newly synthesized DNA strand, but not the template