，则硼氮苯的二氯取代物B₃H₃H₄Cl₂的同分异构体的数目为(    )

A.2                    B.3                     C.4                        D.6

苯的二氯取代物有3种，则硼氮苯的二氯取代物B₃N₃H₄Cl₂的同分异构体数目为(    )

A.2                   B.3                   C.4                   D.6

则硼氮苯的二氯取代物 B₃N₃H₄Cl₂的同分异构体的数目为（　　）

A.2                   B.3                     C.4                      D.6

则硼氮苯的二氯取代物B₃N₃H₄Cl₂的同分异构体的数目为(    )

A.2                    B.3                         C.4                    D.6

则硼氮苯的二氯取代物B₃N₃H₄Cl₂的同分异构体的数目为(    )

A.2                  B.3                       C.4                    D.6