The centripetal force acting on a satellite in orbit
a. acts as an unbalanced force on the satellite.
b. changes the direction of the satellite.
c. is a center-directed force.
d. all of the above

The centripetal force (of gravity) on a satellite in orbit is an
unbalanced force (because there's no equal force pulling
the satellite away from Earth), changes the direction of the
satellite (into a closed orbit instead of a straight line), and
always acts toward the center of whatever curve the satellite
happens to be on at the moment.

Some type of thing that was invisible