Answer:
[ where
is number of months]

Step-by-step explanation:
Pool pass cost for first month =$30
Pool pass cost after first month = $15 for each month
The total amount charged by the pool can be expressed as a function
where
represents the number of months.

This can be simplified by using distribution.



Take 15 as greatest common factor.
∴ 
For 



∴ Amount charged by pool for 12 months = $195
1, A and D are the same thing But I would go with C. Hope this Helps!
I say the answer is point c from the way the points are on the graph
Differentiating once, we have

Differentiating again,


as needed.