Answer:
The V (Bottom left)
Explanation:
The top left is NOT a function because it fails the vertical line test. In fact, it is a vertical line.
The top right is NOT a function because it also fails the vertical line test. This graph may be considered as an inverse of a different function but it will not be a true inverse.
The bottom left IS a function because it passes the vertical line test. It has 1 x value for every y value.
The bottom right is NOT a function because it fails the vertical line test. At most x values, it has 2 y values.
The vertical line test is an imaginary line that you draw to test a function. If only 1 point hits the vertical line, then it is a function. The vertical line can be placed at any point in the graph.
Hope that helps