Weightlessness experienced in a spaceship is due to
A. Absence of Inertia
B. Absence of gravity
C. Absence of accelerating force
D. Freefall to the spaceship

Hint: Weightlessness is a kind of feeling due to the external factor. We can feel this weightlessness in the water, free fall, and absence of gravity. These all factors have certain limitations. But in space, at a certain height from the ground, gravity is absent.

Complete step by step solution:
Option (A)
Inertia means it’s a kind of restriction force on the motion of an object. So it does not feel like weightlessness due to motion. So option A is incorrect.
Option (C)
Acceleration is simply defined as the rate of change of velocity. So it also does not feel like weightlessness.
Option (D)
The free fall of the object is due to gravity. So the free fall to the spaceship is not a correct reason for the weightlessness experienced in a spaceship.
Option (B)
The absence of gravity is a correct and suitable reason for the weightlessness of the spaceship. If there is no downward force acting on a spaceship it means it will float in space. This flotation will feel like the experience of the weightlessness of a spaceship.
Hence option B is correct.

Note:
Weightlessness is experienced by some factors, like in water, free fall, and gravity. If we swim in the water, at that time, we feel like our mass is reduced by half. It's because of the water. The next factor is free fall. If our spaceship falls free from some height from the atmosphere, that time we feel weightlessness. But after a certain time, we will crash into the ground. Only for a short period of time, we will feel weightlessness by the factor of free fall. But the absence of gravity has no certain condition and time limits. In space, there is only one reason for feeling like weightlessness due to the absence of gravity.