Which of the Following Exemplifies Talking Over Someone's Head

Which of the following exemplifies talking over someone's head?

A) The designers did not know accounting jargon and tuned out when the speaker started talking about LIFO and FIFO.
B) The production associates were interested in hearing the advantages of the new security system that was being installed in the shop.
C) The administrative assistants reluctantly attended the company meeting where the new benefits package was being unveiled.
D) The department managers were a little annoyed that the speaker kept defining business terms that everyone already knew.
E) The speaker paused occasionally to make sure everyone in the audience could follow the discussion easily.