The correct answer is:
C. The polygon with 8 sides and a concave shape (attached)

Answer:
There is nothing there...
Step-by-step explanation:
There is nothing at all.
Answer is slope of 5
Step by step
You can graph the slope as seen on the attached picture. You go up 30, you go right +6. Slope is y/x, so 30/6, equals 5
You can also use the slope formula
(y2-y1) over (x2-x1)
Using points on the graph
(6,0) and (0,-30)
(-30-0 ) over (0-6)
-30 over -6
-30/-6
= 5
The answer relies on whether the balls are different or not.
If they are not, which is almost certainly what is intended.
If they are, the perceptive is a bit different. Your
expression gives the likelihood that a particular set of j balls
goes into the last urn and the other n−j balls into the other urns.
But there are (nj) different possible sets of j balls, and each of
them the same probability of being the last insides of the last urn, so the
total probability of completing up with exactly j balls in the last
urn is if the balls are different.
See attached file for the answer.