下列反常积分中, 收敛的是
A
$\int_0^{+\infty} \frac{1}{\sqrt{x^2+x}} \mathrm{~d} x$.
B
$\int_0^{+\infty} \frac{1}{\sqrt{x^3(x+1)^3}} \mathrm{~d} x$.
C
$\int_0^{+\infty} \frac{1}{\sqrt[3]{x^3+x^2}} \mathrm{~d} x$.
D
$\int_0^{+\infty} \frac{1}{\sqrt{x^3+x}} \mathrm{~d} x$.
E
F