Finish the following sentence with the best choice: If you suspect someone is checking you out

Choices:
- Belch. If they belch back, they were. belching is visually contagious.
- Yawn. If they yawn back, they were. Yawning is visually contagious.

Answer:
Yawn. If they yawn back, they were. Yawning is visually contagious.