I've got a quiz (an exam, really).  I've got 5 questions, each worth 25 points.  Canvas thinks the exam is worth 125 points and normally it would be.

HOWEVER

I have instructions for the students telling them to pick only 4 out of the 5 questions (the idea being that they can spend more time on each question but they won't lose a ton of points if they happen to be weak on the limited number of questions I'm asking).
(Side-note: the students can ONLY answer 4 questions.  I mean, they can answer all 5 but only 4 will be graded)

How do I tell Canvas that I want the quiz (exam) to be worth 100 points, instead of the sum of the questions?