If you create a multiple choice question and enable the checkbox "Different points for each answer"
Assume the following
Answer A is worth 2 point.
Answer B is worth 1 point.
Answer C is worth 1 point.
Answer D is worth 0 point
Answer E is worth 0 point
The user selects answers A,B,C,D,E as correct answers. This will give the user 4 points. The user will get the highest points possible.
In this condition, if the student ALWAYS selects all the answers, they will always get the highest points possible scored for this type of question. There needs to be a -1 point deduction on selecting wrong answers. This way, students will not select all the possible answers as correct and get a point deduction when selecting wrong answers.