Index TAB 1X1 was created as shown below:
CREATE INDEX tablxl ON tab1(col_1)
Which modification to index TAB 1X1 can be performed with an ALTER INDEX
statement?

A.
ALTER INDEX tablxl ADD COLUMN (col_2)

B.
ALTER INDEX tablxl CLUSTER

C.
ALTER INDEX tablxl COMPRESS YES

D.
ALTER INDEX tablxl PCTFREE 40