A student says that the function f(x)=3x4+5x2+1 is an even function.

Is the student's statement true or not true, and why?
The student's claim is true, because for any input of x,
f(x)=−f(x).
The student's claim is true, because for any input of x,
f(x)=f(−x).
The student's claim is not true, because for any input of x,
f(x)=f(−x).
The student's claim is not true, because for any input of x,
f(x)=−f(x).