Calculate the second-order partial derivatives.
f(x, y) = 5 x^3 + 3 x^2 y + 4 xy^2
a) fxy = fyx = 30 x + 6 y, fxx = 8 x, fyy = 6 x + 8 y
b) fxy = fyx = 6 x + 8 y, fxx = 6 x + 8 y, fyy = 6 x + 8 y
c) fxy = fyx = 8 x, fxx = 6 x + 8 y, fyy = 3 x^2 + 8 xy
d) fxy = fyx = 8 x, fxx = 30 x + 6 y, fyy = 30 x + 6 y
e) fxy = fyx = 6 x + 8 y, fxx = 30 x + 6 y, fyy = 8 x
f) None of these.