One of the Best Proofs That Our Theory of How

Multiple Choice

One of the best proofs that our theory of how the solar system formed is correct is that astronomers now observe

A) Pluto's orbit, which is not in the plane (or disk) that the other planets orbit in
B) disks around other stars which show evidence of gaps where planets may be forming
C) planets that are called "hot Jupiters"
D) no water in the inner solar system
E) UFO's with alien astronomy textbooks inside, discussing the same theories