This is a test of commonsense with single/multi-choices. Complete the next sentence:

How to repair a cracked surfboard
Clean the board and let it dry overnight.
Wipe the board down with a damp cloth to remove wax, salt, and sand. Use a cotton swab to clean out the crack, and let the board dry overnight for at least 6 hours.

Choices:
(a). Before you begin working, squeeze the crack to make sure no water leaks out. If the crack is still wet, or the board feels heavier in that area, allow it to dry for another 1-2 days before beginning your repairs.
(b). Break up your surfboard into four quadrants. This will create a unique mixture of tough and soft board material.
(c). If the board continues to crack for more than a week, do not attempt to repair it yourself. Using an electric flathead screwdriver is the only solution, and it can strip down your board, leaving you with extremely cracked boards.
(d). When brushing the broken board, make sure to work all around the crack, and all under the band at the rear. Repair damaged surfboards online or through auto parts stores.
The answer is:
(a).