Mark against the correct answer in each of the following:

Mark $(\sqrt{ })$ against the correct answer in each of the following:

$\int \frac{\log x}{x} d x=?$

A. $\frac{1}{2}(\log x)^{2}+C$

B. $-\frac{1}{2}(\log x)^{2}+C$

C. $\frac{2}{x^{2}}+C$

D. $\frac{-2}{x^{2}}+C$