It is known that the Maclaurin series function f(x) = tan x is

tan x = x + 1/3 x^3 + 2/15 x^5 + ....

Then the fourth derivative of the function g(x) = (1 + x^2) tan x at 0 is g^5(0) =

a) 48

b) 56

c) 64

d) 72

e) 84

f) 96