For $x\in R-\{0,1\}$, let $f_1(x)={1\over x}$, $f_2(x)=1-x$ and $f_3(x)={1\over1-x}$ be three given functions. If a function, $J(x)$ satisfies $(f_2.J.f_1)(x)=f_3(x)$ then $J(x)$ is equal to :

(1) $f_3(x)$

(2) $f_1(x)$

(3) $f_2(x)$

(4) ${1\over x}f_3(x)$

(1) $f_3(x)$

(2) $f_1(x)$

(3) $f_2(x)$

(4) ${1\over x}f_3(x)$