Which statement best describes how to determine whether f(x) = x⁴ – x³ is an even function?
(A) Determine whether (–x)⁴ – (–x)³ is equivalent to x⁴ – x³.
(B) Determine whether (–x⁴) – (–x³) is equivalent to x⁴ + x³.
(C) Determine whether (–x)⁴ – (–x)³ is equivalent to –(x⁴ – x³).
(D) Determine whether (–x⁴) – (–x³) is equivalent to –(x⁴ + x³).