Answer: C. Archie needs to achieve a perfect score on his next dive.
Step-by-step explanation:
From the passage it is shown that the next dive is Archie's last dive and for him to be able to win the gold, he must achieve an almost perfect score which means therefore that the central idea is that Archie needs a perfect score in this next dive.
The rest of the passage centers on this notion by expanding on how he can get this perfect score or at least more points and the ways he can still win if he does not as well as the effects of not winning.