The range of values of k for which the function f(x) = (k2 - 4)x2 + 6x3 + 8x4 has a local maxima at point x = 0 is

• A. k < -2 or k > 2
• B. k ≤ -2 or k ≥ 2
• C. -2 < k < 2
• D. -2 ≤ k ≤ 2