It is possible to experience weightlessness in a spacecraft flying through space:
a. Only when you are in a circular orbit around a planet, moon, or star
b. Only when you're very far from any massive bodies like planets, moons, or stars
c. In any set of circumstances, since you're always weightless in space, regardless of whether the engines are firing or not
d. Only when you are drifting and the engines are shut off"