Witch statement best describes how to determine whether f(x) =x^3+5x+1 is an even function?

A.Determine whether –(x3 + 5x + 1) is equivalent to x3 + 5x + 1. b.Determine whether (–x)3 + 5(–x) + 1 is equivalent to x3 + 5x + 1.
c. Determine whether –x3 + 5x + 1 is equivalent to –(x3 + 5x + 1).
d. Determine whether (–x)3 + 5(–x) + 1 is equivalent to –(x3 + 5x + 1)

A function is even if f(x) = f(-x) for all x.

f(-x) = -x³ + 5(-x) + 1
f(-x) = -x³ - 5x + 1

b.Determine whether (–x)3 + 5(–x) + 1 is equivalent to x3 + 5x + 1. 

What class is this? i have no idea and i'm not going to give you the wrong answer. do you have a graph that goes with all the questions