A

$\displaystyle\int_1^{+\infty}\dfrac{dx}{x}$

B

$\displaystyle\int_1^{+\infty}\dfrac{dx}{\sqrt{x}}$

C

$\displaystyle\int_1^{+\infty}\dfrac{dx}{x^2}$

D

$\displaystyle\int_1^{+\infty}\dfrac{\ln^3x}{x}dx$