Isn't a hypothesis making a theory? Based on that I guess the answer would be A. Making a theory, because you making the hypothesis is not part of testing it.
Because it is physically true day really know that by just knowing it very well
Answer:

Explanation:
using the law of the conservation of energy:


where K is the spring constant, x is the spring compression, N is the normal force of the block,
is the coefficiet of kinetic friction and d is the distance.
Also, by laws of newton, N is calculated by:
N = mg
N = 3.35 kg * 9.81 m/s
N = 32.8635
So, Replacing values on the first equation, we get:

solving for
:

Answer: What is this supposed to be converted into?
Explanation: