Correct the sentence below.
the cameras of the voyager ii spacecraft detected six small, previously unseen moons circling uranus, which doubles to twelve the number of satellites now known as orbiting the distant planet.

(a) which doubles to twelve the number of satellites now known as orbiting

(b) doubling to twelve the number of satellites now known to orbit

(c) which doubles to twelve the number of satellites now known in orbit around

(d) doubling to twelve the number of satellites now known as orbiting

(e) which doubles to twelve the number of satellites now known that orbit