Respuesta :

You need to rethink ...
  4, 8, 11

4. 3.14 is a terminating decimal, so is rational. (Looks like π, but isn't π.)
8. √9 = 3, a rational number
11. Your choice gives √0 = 0, a rational number.

12. √20 is irrational. 20 is not a perfect square.