Final answer:
Olivia decides to announce the winner of the contest to celebrate their achievement and give them recognition for their accomplishment.
Step-by-step explanation:
Olivia decides to announce the winner of the contest because it is an important moment and a way to celebrate the achievement. By announcing the winner, Olivia acknowledges their accomplishment and gives them the recognition they deserve. Additionally, announcing the winner can create a sense of excitement and build anticipation for future contests or events.