This is a test of commonsense with single/multi-choices. Complete the next sentence:

How to disable a garage door sensor
Ensure that the door is closed, if possible.
Engaging manual mode on your garage door while it's open may cause it to come crashing closed if the door spring is damaged. Avoid this by setting it to manual mode while the door is closed.

Options are:
a). The manual mode setting should be set to " off " or " auto " as opposed to " on. " Determine if you can shut off your car's garage door.;
b). Reverse all irrelevant changes that would result in the door spring finally shutting after using manual mode when the garage door is shut. Because the door spring latch is a key feature of garage doors, none should be tampered with, regardless of whether the door spring is unlocked or not.;
c). If you have to disable manual mode on the garage door, it will be turned on manually. If you're worried about it tottering open, this is an option that you can use when you unlock the door to find the door moving.;
d). If this is impossible because the door is stuck open, move on to the next step. Prop the door up with 2x4s if it's stuck open.;
The answer is:
d).