5. The function $f(x)=a x^{4}+b \sin ^{3} x+c x^{2}+d x+$ 2 satisfies $f(1)=7, f(-1)=9$ and $f(2)+f(-2)$ $=124$. Then $f(\sqrt{2})+f(-\sqrt{2})=(\quad)$.
(A) 34
(B) 36
(C) 38
(D) 40
5.D.

Using $f(1)=7, f(-1)=9$ we get $a+c=6$;
Using $f(2)+f(-2)=124$ we get $32a+8c=120$.
Thus, $a=3, c=3$. We have $f(\sqrt{2})+f(-\sqrt{2})=40$.