Final answer:
The correct statement about helicopters is that if the helicopter must land on a grade, you should approach it from the uphill side.
Step-by-step explanation:
The correct statement about helicopters is C. If the helicopter must land on a grade, you should approach it from the uphill side. This is because landing on a grade can cause the helicopter to tilt, and approaching from the uphill side helps to prevent further tilting and maintain stability. Approaching from the downhill side could lead to an unstable landing.