I believe the answer should actually be
C.) It is a one to one function
A one to one function is a function in which the x and y values never repeat. Each value of x is different every time, and they never have the same values of y.
Answer:

Step-by-step explanation:
Let x represent the number of times Giselle uses the athletic club and y represent money left in account.
We have been given that each time she uses the club, $15 is deducted from the account. The amount used after using the club after x times would be
.
We are also told that Giselle pays $220 in advance on her account at the athletic club.
The money left in account after x uses of athletic club would be money in account initially minus amount used for using the club x times.

Therefore, our required equation would be
.
Answer:
12-x²
Step-by-step explanation:
I hope this helps you, please give me brainliest