What is the most logical next event?

How to prevent a car from rolling back on a hill
Come to a complete stop.
When you are on a slope, you need to come to a complete stop using either the brake pedal or the handbrake. This holds true whether you're facing up a slope or down a slope.

OPTIONS:
* In modern winter conditions, a complete stop is used only if you are approaching a fallen tree branch, as doing so may trigger a car to back up. Make sure you have adequate brake fluid.
* Once you get on the slope, your car will stop as soon as it reaches the top. If you're traveling on a hill, you can try to bring your car to a complete stop at any points where it might start to back up.
* Some drivers prefer to use the handbrake, because it frees up their right foot to use on the gas pedal when they intend to start driving again. Use hill-start assist, if available.
* Keeping a straight line will cause you to pull out of something fatal. To avoid falling, keep your shoulders, chin, and head straight ahead and wait for a watch indicator to light up slowly.
Some drivers prefer to use the handbrake, because it frees up their right foot to use on the gas pedal when they intend to start driving again. Use hill-start assist, if available.