Answer:
Choice B.
Step-by-step explanation:
In a function, each x-coordinate can only appear in one single point. In a relation, if more than one point have the same x-coordinate, it is not a function.
Apply the vertical line test.
Imagine a vertical line starting at the left of the graph and moving to the right.
If the line in any position intersects more than one point of the relation, then the relation is not a function.
If the line in every position only intersects one point at a time, then the relation is a function.
Start with Choice A.
A vertical line starts at the left and moves right. It intersects point (-4, 3) by itself. Then it intersects point (-2, 1) by itself. When the vertical line gets to x = -1, it intersects two points, (1, -1) and (-1, 4). This means it is not a function.
Choice B.
Any vertical line in any position intersects at most one point at a time. Choice B is a function.
Choice C.
At x = -2 and at x = 2, a vertical line intersects two points. This is not a function.
Choice D.
At x = 0, a vertical line intersects two points. This is not a function.
