Final answer:
The young man in the scenario is exhibiting the defense mechanism of displacement by drinking heavily after his wife dies of cancer.
Step-by-step explanation:
In the given scenario, the defense mechanism being exhibited by the young man is displacement. Displacement is a defense mechanism in which someone redirects their feelings or impulses from the original target to a substitute target. In this case, the young man is channeling his grief and anger from the death of his wife into drinking heavily.
Displacement can occur when someone is unable to directly express their emotions or feelings towards the original source, so they redirect them onto something or someone else. By engaging in heavy drinking, the young man is using alcohol as a substitute target for his emotions.