The Primary Difference Between the Topic of a Message and the Main

The primary difference between the topic of a message and the main idea is

A) the topic is more specific than the main idea.
B) the main idea is more specific than the topic.
C) the topic is what you see as most important, whereas the main idea is what your audience sees as most important.
D) the main idea is what you see as most important, whereas the topic is what your audience sees as most important.
E) none of the above-there is no real difference between the two.