<human>: Here is a goal: If you suspect someone is checking you out

Which way makes more sense to accomplish this goal?

OPTIONS:
- Belch. If they belch back, they were. belching is visually contagious.
- Yawn. If they yawn back, they were. Yawning is visually contagious.
<bot>: Yawn. If they yawn back, they were. Yawning is visually contagious.