$f(x)=1+{\displaystyle \underset{n=1}{\overset{}{}}}\frac{1*3*5\text{c}\text{d}\text{o}\text{t}\text{s}(2n-1)}{2*4*6\text{c}\text{d}\text{o}\text{t}\text{s}*(2n)}{x}^n$ olsun. $|x|<mn>1</mn>$ i$$in $2(1-x)f^{\text{'}}(x)$ ifadesi a$$a$$daki $$klardan hangisinde verilmi$$tir$?$

a$)f(x)-1$

b$)f(x)+1$

c$)xf(x)$

d$)(1-x)f(x)$

e$)f(x)$