luisafuzaro Eu acho que é a alternativa D, pois a raiz de 9 é 3

Astaeim Primeiro fatoramos                                          729|3
                                                                        243|3
                                                                          81|3
                                                                          27|3
                                                                            9|3
                                                                             3|1
                                                                             1|
depois voltando a equação dará 9/3√3                                                                              que vamos simplificar dando 3/√3                                                                                      quando temos raiz no denominador temos que racionalizar                                                 logo dará 3√3/√3²que vamos simplificar por 3                    logo dará  √3
 
sendo assim a resposta é a (B)