Which of the Following Statements Are True and Which Are

Which of the following statements are true and which are false?
A) The speaker's tone may be the opposite of his/her meaning.
B) Ironic speech means expressing meaning through language signifying the opposite. This cannot be done in writing.
C) The writer can express irony in words only, whereas the speaker can use his/her voice and gestures in an ironic way.
D) The speaker is wise to emphasise points through repetition, otherwise the audience may forget them.
E) In writing company reports, the professional communicator should use the language of magazines: cheerful, colourful and colloquial.