How Does the Specific Purpose Statement Differ from the Central

How does the specific purpose statement differ from the central idea?

A) Whereas your central idea indicates what you want your audience to do when you have finished your speech,your specific purpose identifies the essence of your message.
B) Whereas your central idea indicates the overarching goal of the speech,your specific purpose identifies the essence of your message.
C) Whereas your specific purpose indicates what you want your audience to do when you have finished your speech,your central idea identifies the essence of your message.
D) Whereas your specific purpose indicates the overarching goal of the speech,your central idea identifies the essence of your message.