The Answer is D cause of the people going back and forth.
I believe it is b. you only want to change one thing at a time so you know which one thing caused the effect
Answer: the new force will be 1/9 of the original force
Explanation: Please see attachment for explanation
1109, 5.9 * 10 squared, -0.041, -4.2 times 10 to the -3, and -7.6 times 10 to the -5
Hope this helps