You can just do rise over run to find the slope or use the slope equation which is

3=x1
0=x2
5=y1
-1=y2
input those and you can get the slope graphed.
Ummm what mush is it is a good thing you can get it to get it and you can see it and then get it done
Let

denote the event that a student is a freshman,

a sophomore,

a junior, and

a senior.
Let

denote the event that a student majors in engineering. By the law of total probability,

By the definition of conditional probability, we can expand each of these intersection probabilities to get

A is the right answer I think