为了获取GV$SQL视图的定义，以下哪个方法可以得到正确的视图定义？（D） A select text from dba_views where view_name = 'GV$SQL' and owner='SYS'; B select view_definition from gv$fixed_view_definition where view_name='GV_$SQL'; C select dbms_metadata.get_ddl('VIEW','GV_$SQL','SYS') from dual; D select view_definition from gv$fixed_view_definition where view_name='GV$SQL';