The correct answer to this open question is the following.
Unfortunately, you forgot to include the options for this question. We do not what are the possible statements to answer the question.
However, trying to be of some help, we can comment on the following general terms.
If I was a historian researching Martin Luther's "95 Theses," the most important element for my research would be the criticism Luther give to the Catholic church clergy regarding the selling of indulgences.
This would help me to better understand the point of view and the perspective of German monk Martin Luther because his criticism had important consequences to the degree that this created a split in the church and the beginning of Protestantism in Europe.
After all this commotion, the Pope ordered a counter-reformation movement to try to fix somethings that have hurt the Catholic church.