Benjamin Bloom in His Study of American's Top Concert Pianists,tennis

Benjamin Bloom in his study of American's top concert pianists,tennis players,Olympic swimmers,and mathematicians found that

A) when they were children their skills were rather ordinary at first.
B) their talent just "magically" surfaced one day.
C) the majority of them were not exposed to expert coaching until they were older adolescents or young adults in national competitions.
D) they require less practice of their craft each day than a successful, but less eminent, person in their field.