Answer:
C. greater than D, but less than 2D
Step-by-step explanation:
The amount of potential energy in the system is a function of the compression of the spring. That is the same for both masses.
The potential energy is transferred to kinetic energy when the spring is released. The kinetic energy is jointly proportional to the mass and the square of the velocity. That is, the velocity is inversely proportional to the square root of the mass, for the same kinetic energy.
The horizontal distance traveled will be proportional to the launch velocity. So a halving of the mass will increase the velocity by a factor of ...
v2 = v1·√(1/(1/2)) = v1·√2
This means the second mass will land at a distance of about D√2, a value ...
greater than D but less than 2D.