Which of the Following Is the Central Factor for the Crime

Which of the following is the central factor for the crime of solicitation?

A) An overt act by the solicitor toward committing the crime
B) An initial attempt by the solicitor before finally seeking another to commit the crime
C) The solicitor of the crime asks, encourages, commands or otherwise entices another to do the actual act without any act toward committing the crime by the solicitor
D) There has to be multiple parties involved in the solicitation