Correct answer is (a) \(\frac{\sqrt{9}}{2}\)
Easy explanation: \(\frac{\sqrt{9}}{2} = \frac{3}{2}\) where 3 and 2 are integers. So \(\frac{3}{2}\) is rational number by definition.
π ≈ 3.14, \(\sqrt{3}\) ≈ 1.73 \(\sqrt{11}\) ≈ 3.31
As we can see that none of the above three numbers is integer so they are not rational number by definition. (Rational number = p/q where p and q are integers and q ≠ 0).