Only number 7. I’ll give 5 stars, (which of the following relations represent functions? Select all that apply)

A. not a function
B. function
C. function
D. function
E. not a function

explanation:
A. The input C cannot have two different outputs.
B. The different x inputs can all have the same y output of 3.
C. Use vertical line test and see that no two points will touch the vertical line at the same time.
D. This is a standard linear function.
E. Use vertical line test (like in C.). You will notice that there’s two intersection points of you draw a vertical line through it, so it is not a function.