Correct option is (B) √9
\(\because\) Square root of prime numbers is always an irrational number.
\(\because\) 2, 3 & 7 are prime numbers.
\(\therefore\) \(\sqrt2,\sqrt3\,,\&\,\sqrt7\) are irrational numbers.
Now, \(\sqrt9=\sqrt{3^2}=3\) which is a rational number.
