The American heart association changed ABC (Airway, Breathing, Compressions) to CAB (Compressions, Airway, Breathing) because when the ABC sequence to perform CPR was performed, people would spend so much time trying to open the airway that there was a delay in chest compressions making rescue breathes harmful. With the new CAB sequence people initiate chest compressions sooner and ventilation is only slightly delayed.
Hope this helps!
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.