要删除Student表的Birthyear列,同时删除所有引用该列的视图和约束。下列哪一个SQL语句正确表达了这一删除要求()。
AALTERTABLEStudentDELECTBirthyearRESTRICT
BALTERTABLEStudentDELETEBirthyearCASCADE
CALTERTABLEStudentDROPBirthyearRESTRICT
DALTERTABLEStudentDROPBirthyearCASCADE
AALTERTABLEStudentDELECTBirthyearRESTRICT
BALTERTABLEStudentDELETEBirthyearCASCADE
CALTERTABLEStudentDROPBirthyearRESTRICT
DALTERTABLEStudentDROPBirthyearCASCADE