I'm going to be installing an American Standard bathtub. I have placed a 2x4 as a stringer on the wall the length of the tub. Here is my question:

How do i secure the tub to the wall?

Few possiblities people are telling me.

1. Leave it
2. Drill a hole through the flange and countersink drywall screws to the stud
3. Screw in a secrew just above the flange in the stud to prevent it from going up.

Any suggestion on the best way to do this or the correct way to do this would be appreciated.