Let 'f' be a function such that f(xy)=f(x)f(y)∀x,yϵR+ and f(1+x)=1+x(1+g(x)) where limx→0g(x)=0.Then ∫₁²f(x)/f′(x).1/1+x² dx=
A. 2 ln 5/2
B. 4 ln 3/2
C. 3 ln 2
D. 1/2 ln 5/2