In "How to Encourage Creativity", what role(s) can teachers play in encouraging students' creativity, according to the author?

A. Teachers should help students learn necessary skills to become more creative.
B. Teachers should try their best to find and foster students' natural ability unconditionally.
C. Teachers should be particularly brilliant to act as role models for students.
D. Teachers should use their connoisseurship, judgment and creativity in the process.