Concept:A "bout" is the specific word used for a boxing match or contest.
Explanation:The passage describes Jim's first professional boxing contest.
In boxing terminology, a single match between two opponents is known as a bout.
This match took place when he was seventeen, so gap 71 refers to that fight.
Option A, "session", means a period spent in an activity, not a competitive match.
Option B, "attempt", means an effort to do something, so it is not correct.
Option C, "entry", refers to joining a competition rather than the contest itself.
Therefore, only option D suits the context of a boxing fight.
Answer:D. bout