[题目]-|||-设f(x)为连续函数,且 (x)=(int )_(dfrac {1)(x)}^ln xf(t)dt, 则F'(x)等于 ()-|||-(A) dfrac (1)(x)f(ln x)+dfrac (1)({x)^2}f(dfrac (1)(x)) (B) (ln x)+f(dfrac (1)(x))-|||-(C) dfrac (1)(x)f(ln x)-dfrac (1)({x)^2}f(dfrac (1)(x)) (D) (ln x)-f(dfrac (1)(x))