Finish the following sentence with the best choice: How do I know if I am successfully removing the air bubbles from concrete while pouring when making a countertop?

Choices:
- When vibrating or rapping the mold, you should see air bubbles on the surface if it's working
- When vibrating or rapping the mold, you should see water bubbles on the surface if it's working

Answer:
When vibrating or rapping the mold, you should see air bubbles on the surface if it's working