Answer:
A. 70N
Explanation:
It's more complicated than force. Airbags deploy when you're going fast enough to need them, and the collision sensor experiences enough deceleration to assume you're in a collision. It could take very little force directly on top of the sensor, or a lot of force in the middle of your bumper. The airbag computer runs a pretty sophisticated algorithm to decide whether to deploy the airbags, and it's tuned for the design of each car.
