Answer:
The answer is D.
Step-by-step explanation:
According to the information given in the example, Zack is most likely to have suffered damage to his brain's frontal lobe becasue of the symptoms that he show such as a change of personality. Frontal lobe is located at the front of the brain and it is responsible for controlling functions such as judgements, decision making, personality traits, emotions and memory which are all among the most important things for someone to function properly. So the correct answer is D.
I hope this answer helps.