With Regard to Football, Which of the Following Is True

With regard to football, which of the following is true?

A) American football gradually evolved from rugby and soccer; these two sports were played at Harvard, Princeton, Yale, Rutgers and Columbia.
B) Walter Camp replaced the rugby "scrummage" with the line of scrimmage.
C) Walter Camp determined that football would be played with 11 athletes on a team and each athlete became a "specialist" and was assigned a specific position, a characteristic of modern sport.
D) All of the above.
E) B and C only.