Which of the following statements best describes the significance of the term "fully adult" in the context of artistic development and maturity in the arts?
A) "Fully adult" refers to an artist's chronological age being over 21 years old.
B) "Fully adult" signifies an artist's complete technical mastery and creative maturity.
C) "Fully adult" indicates the artist's ability to work independently without mentorship.
D) "Fully adult" means the artist's work is legally recognized and protected under copyright law.