Since the no of question is 6
Since the total score if they are all correct is 8
Then the score of one question will be

Since y is the score of the student, and x represents the no of the questions he answered wrong, then the equation will be

Since the form of the equation is y = m x + b, where
m is the slope
b is the y-intercept
By comparing them
m = -4/3
b = 8
So look for the graph that has y-intercept = 8
And its direction from left to right
The parts cutting from y-axis is 4 and from x-axis is 3
Let us find the graph
It is the first graph
Do you see it?