Microgravity condition is achieved in the ISS because of what?

Question

A. it is very far away from the Earth

B. it is constantly falling towards the Earth

C. it is orbiting in the opposite direction of the Earth's spin

D. the mass of ISS is very much smaller compared to the mass of the Earth

Then, can you explain the answer?

Answer 1

B is the most accurate, but it is an odd way of putting it. Usually you would say "it is in orbit".

An object in orbit is constantly falling, but because of its forward momentum it never hits the thing it is orbiting. That goes for the ISS and anything inside it. Because gravity accelerates all things equally, the people and objects inside the ISS follow exactly the same trajectory as the ISS itself. The effect is that things inside the ISS experience virtually no acceleration in any direction, in other words, microgravity.