George ruined the surprise. How did he do so?
Options:
- hiding
- accidentally
- expectation
- knowingly
- planned
Let's think now! Step-by-step reasoning:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
One can ruin surprise knowingly. Someone can knowingly ruin something easily.
So, the final answer is knowingly.