Answer:
B.) Greater than one
(at least I am pretty sure I am sorry if I am wrong I tried my best)
Explanation:
I think it is greater than one because it moves a short distance but it still is very helpful. The doorknob doesn't do much it just turns over and opens up a door. But, a doorknob CAN do much more. A doorknob can lock and keep things that you don't want inside out. It can also keep a door closed.