It is necessary because if you don't have a confirmed opinion with textual evidence to back it up you wont have a good argument.
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
