Question

I WILL GIVE BRAINLIEST TO WHOEVER IS CORRECT.

Answer 1

In a function, each x-coordinate can be used only once.
If you have two points, one above the other on the same vertical line, it is not a function.
You are correct.

Answer 2

The upper, right-hand graph represents a function.  Why?  Because there is never more than one value of y for any given x.

If you use the vertical line test on the other 3 problems, you'll see that for some x, the line goes thru more than just one black dot.