5. Let the sum of two non-zero real numbers be 4 times their product. Then the sum of the reciprocals of these two numbers is ( ).
(A) 1
(B) 2
(C) 4
(D) 8
(E) 12
5. C.

Let two non-zero real numbers be $x, y$. From the problem, we have
$$
x+y=4 x y \Rightarrow \frac{1}{x}+\frac{1}{y}=4 .
$$