Evaluate the improper integral or show that it diverges.

${\displaystyle \underset{0}{\overset{7}{}}}\frac{dx}{\sqrt[\phantom{2}]{49-x^2}}$

Select the correct choice and, if necessary, fill in the answer box to complete your choice.

A$.$ The improper integral converges and ${\displaystyle \underset{0}{\overset{7}{}}}\frac{dx}{\sqrt[\phantom{2}]{49-x^2}}=($Type an exact answer, using $x$ as needed.$)$

B$.$ The improper integral diverges.