Graph 4 is an Even function.
Solving this question means we have to find out the meaning of an even function graph.
By definition, a graph that represents an even function is usually one where the points are symmetric about the y-axis. This means the y-coordinate to a point on the left of the y-axis must be mirrored as the same on the point to the right.
Let's look at the graphs in the options;
Graph 1; we see at the left bottom that the point there has a coordinate of (-6, -4) while at the right bottom, we see that the coordinate is (4, -2). Since the y-values are not same, then it is not an even function. Graph 2; Looking at the graph, there is no point that is mirrored to the right at all. Thus it is not an even function. Graph 3; Just like in graph 3,there is no point that is mirrored to the right of the y-axis and thus it is not an an even function. Graph 4; In this graph, it is clear that all points on the left are mirrored  to the right side of the y-axis. Every point on the left has same y-value as the corresponding one on the right. Therefore, it is an even function.
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