The answer is D. If you aren't consistent with your drop positions, then your data may be invalid. To be frank: it basically screws over the experiment.
Yes, ratio can be expressed in percentage.
The correct answer is
"As the distance from the earth increases, the gravitational pull on the spaceship would decrease."
In fact, the gravitational force (attractive) exerted by the Earth on the spaceship is given by

where G is the gravitational constant, M the Earth's mass, m the mass of the spaceship and d the distance of the spaceship from the Earth. As we can see from the formula, as the distance d between the spaceship and the Earth increases, the gravitational force F decreases, so answer D) is the correct one.
Explanation:
By Hooke's Law,
F=kx
The only force acting here is weight, and x is the extension of the string (you need to convert this to mm) so
mg=kx
(0.15)(9.81)=k ((420-300)x10^-3)
Then just solve this equation.
Answer:
F = G M m / R^2 gravitational force on planet of mass m.
None of these quantities change in the given hypothesis so
there will be no change in the orbit of mass m