Which sentence contains a negative-form error in the should, ought to, and had better advice contrast?
You should not store the archive boxes beside that damp wall.
The diver had better not to loosen the valve while the tank is pressurised.✓Correct answer
We ought not to postpone the rehearsal until the opening night.
I had better not cycle across the causeway after the warning siren.
Explanation
The sentence about the valve is erroneous because not must come before the bare verb and no to follows it. The remaining sentences form negative advice correctly with should not, ought not to, or had better not.