Which of the Following Elements Are Essential Features of a Profession

Which of the following elements are essential features of a profession?

A) extensive training, license or certification, and provision of important services to society
B) extensive training, license or certification, and provision of important services to society.
C) extensive training, provision of important services to society, and primarily intellectual skills
D) license or certification, representation by professional organizations, and autonomy
E) license or certification, autonomy, and provision of important services to society