If f(x) is an even function, which statement about the graph of f(x) must be true?
-It has rotational symmetry about the origin.
-It has line symmetry about the line y = x.
-It has line symmetry about the y-axis.
-It has line symmetry about the x-axis.
-It has rotational symmetry about the origin.
-It has line symmetry about the line y = x.
-It has line symmetry about the y-axis.
-It has line symmetry about the x-axis.