Table TAB1 was created using the following statement: CREATE TABLE tab1 (c1 INT, c2 INT, c3 INT, c4 INT, c5 INT); If column C1 is unique and queries typically access columns C1 and C2 together, which statement(s) will create index(es) that will provide optimal query performance? （）

• A、 CREATE UNIQUE INDEX xtab1 ON tab1 (c1) include (c2)
• B、 CREATE UNIQUE INDEX xtab1 ON tab1 (c1);  CREATE INDEX xtab2 ON tab1 (c3) INCLUDE (c2) 
• C、 CREATE UNIQUE INDEX xtab1 ON tab1 (c2, c1)
• D、 CREATE UNIQUE INDEX xtab1 ON tab1 (c2) INCLUDE (c1）