Finish the following sentence with the best choice: How quickly should I grind and polish the concrete when making a concrete countertop?

Choices:
- Do all your grinding and polishing after 4 days but before 10 days so the concrete is stiff enough but not full strength yet
- Do all your grinding and polishing after 4 days but before 10 days so the concrete is stiff enough but not full wetness yet

Answer:
Do all your grinding and polishing after 4 days but before 10 days so the concrete is stiff enough but not full strength yet