B strength training I think that’s the answer
Point 1 is PROBABLY higher up than point 4.
Another possibility is that on the way from Point 1 to point 4,
a lot of people are falling out of the coaster.
We have no way to tell, because you neglected to show us
the picture that goes with this question. It's important.
The answer is radiation I believe
Centripetal force is defined as, "the force that is necessary to keep an object moving in a curved path and that is directed inward toward the center of rotation," while centrifugal force is defined as "the apparent force that is felt by an object moving in a curved path that acts outwardly away from the center of rotation," according to Merriam Webster Dictionary.
The absolute refractive index is equal to the speed of light of the wave in air divided by the speed of light in the second medium. This means that it is equal to 3 x10^8 / 1.71 x10^8. This means the answer is 1.75