The graph show is
a)fails the vertical line test at (2,3) and (2,-2)
b) fails the vertical line test at (2,3) and (-1,3)
c) passes the vertical line test
so the line is
a) a function
b) not a function

First
A)fails the vertical line test at (2,3) and (2,-2)

Second
B) not a function


Further Explanation:

It is possible to pass a single vertical line through this red curve. So it is not a function because it fails the vertical line test. One specific line goes from (2,3) to (2,-2) but there are infinitely other lines to choose from. In order to pass the vertical line test, it must be impossible to pass a vertical line through more than one point on the curve. A function is where any given input leads to exactly one output. In the case of (2,3) and (2,-2), the input x = 2 leads to more than one output (y = 3 and y = -2) at the same time