创建表order_test,内有10行单列数据，其值为随机生成。建表语句如下：ACD create table order_test as select dbms_random.value(1,100) c1 from dual connect by rownum<=10;。 请问，以下哪种创建索引的方法，会导致 select /*+ index(t ind_c1) */ * from order_test t where c1 is not null; 返回的结果是有序的？ A create index ind_c1 on order_test(c1); B create index ind_c1 on order_test(c1) global partition by hash(c1) partitions 2; C create index ind_c1 on order_test(1,c1); D create index ind_c1 on order_test(c1) global partition by range(c1) (partition p1 values less than(51),partition p2 values less than (101),partition p_max values less than(maxvalue));