With Regard to the Development of Greek Sport

With regard to the development of Greek sport

A) the origin of Greek sport has not been clearly established by scholars.
B) there was a sharp distinction between amateur and professional athletes as described by H.W. Pleket and Slowikowski.
C) there are two predominant schools of thought of the development of Greek sport; the traditional "rise -and- fall approach" and the view that Greek sport came about due to contact with other civilizations who practiced sport such as the Egyptians, Crete, and the Phonecians.
D) Agon and Arete were common arguments that were used by philosophers who were opposed to the popularity of Greek athletics.
E) A and C only