Every action has an equal opposite reaction
No. Sadly, you're not right. The whole problem here is the meaning of a few words. "Starts out"is the same thing as "initial" conditions. "At rest" is the same thing as not moving ... zero speed. So if an object starts out at rest, that says that its initial speed is zero ... choice 'b'.
I’m pretty sure it’s speed=distance/time
<span>The momentum before the collision is equal to the momentum after the collision</span>