Which Best Exemplifies Acceleration

Which best exemplifies acceleration?

A) Rose,a six-year-old,goes to a third grade math class because she has mastered first and second grade math.
B) Carter is given more difficult reading material than her classmates in fourth grade because she has mastered reading.
C) Coralee,who has mastered the third grade science curriculum,teaches it to others in her class who have not.
D) Desmond studies subject areas not offered at his school,such as comparative religion and quantum physics.