The discovery of Eris .
A)was not surprising, because other Kuiper belt objects approaching the size of Pluto had already been discovered
B)was not surprising, because the existence of a massive "Planet X" had been predicted nearly a century ago
C)was surprising, due to its "backwards" orbit around the Sun
D)was surprising, since we thought we knew about all large objects in the solar system

Question

Quizplus · Accepted Answer

The discovery of Eris was not surprising because other large Kuiper belt objects similar in size to Pluto had already been discovered, indicating the possibility of more such objects.

The Discovery of Eris