Answer: C. N
N stands for Newtons
In terms of SI units, 1 newton = 1 kg m/s^2
It's based off the equation F = ma, which is Newton's second law.
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Extra info:
- Choice A is velocity
- Choice B is acceleration
- Choice D is some unit I don't really recognize, so I'm not sure if its nonsense or it may have some use. Though I'm sure that N/s isn't a measurement of force.