Why Is the Discovery of Pluto Sometimes Referred to as an Accidental

Multiple Choice

Why is the discovery of Pluto sometimes referred to as an accidental discovery?

A) The observations made to locate Pluto were not made in a systematic manner.
B) Pluto was not located close to its predicted location.
C) No one had ever predicted that Pluto existed before it was found.
D) Pluto's mass was too small to seriously alter the orbit of Neptune.
E) a and c