Moderate means D- to take on a serious mode.
The writer used the word 'moderate' to make a comparison between those people who would lead a serious life without any excess with the group of people who would do whatever they wanted to fight against the Black Death.
Images should match the presentation's meaning and tone.
As she has already prepared and rehearsed several times, we can not say the answer is a or b. Both c and d are really good options but I would say D is the correct one, cause what she needs is to have perspective of what she will attain after her presentation and to do that she needs a positive thinking. Hope this helps