20. $\lim x \rightarrow 0 ( x \tan 2 x - 2 x \tan x ) / ( 1 - \cos 2 x ) 2$ is:
(A) $y = 2$
(B) $y = 2 x$
(C) $y = 2 x - 4$
(D) $y = 2 \times 2 - 4$
20. $\lim x \rightarrow 0 ( x \tan 2 x - 2 x \tan x ) / ( 1 - \cos 2 x ) 2$ is:\\
(A) $y = 2$\\
(B) $y = 2 x$\\
(C) $y = 2 x - 4$\\
(D) $y = 2 \times 2 - 4$\\