The correct answer is option D. Shoking information is an effective way to gain your audience's attention. This is because surprising figures are tipically catchy, that is they catch people's attention. It leaves the reader or hearer wanting to know more about the topic.
On the other hand, a joke, even though it would catch the audience's attention for a minute, it is not useful for attracting the reader or hearer's attention during the entire text. The other options are too formal and they are not attractive to a general audience.
