Which operator can be used with a multiple-row subquery?（）

A. CREATE INDEX NAME _IDX (first_name, last_name);
B. CREATE INDEX NAME _IDX (first_name, AND last_name)
C. CREATE INDEX NAME_IDX ON (First_name, last_name);
D. CREATE INDEX NAME_IDX ON employees (First_name, AND last_name);
E. CREATE INDEX NAME_IDX ON employees (First_name, last_name);
F. CREATE INDEX NAME_IDX FOR employees (First_name, last_name);

A. Must begin with either a number or a letter.
B. Must be 1-30 characters long.
C. Should not be an Oracle Server reserved word.
D. Must contain only A-Z, a-z, 0-+, _, *, and #.
E. Must contain only A-Z, a-z, 0-9, _, $, and #.
F. Must begin with a letter.

A. You use a NEXTVAL pseudo column to look at the next possible value that would be generated from a sequence, without actually retrieving the value.
B. You use a CURRVAL pseudo column to look at the current value just generated from a sequence, without affecting the further values to be generated from the sequence.
C. You use a NEXTVAL pseudo column to obtain the next possible value from a sequence by actually retrieving the value from the sequence.
D. You use a CURRVAL pseudo column to generate a value from a sequence that would be used for a specified database column.
E. If a sequence starting from a value 100 and incremented by 1 is used by more then one application, then all of these applications could have a value of 105 assigned to their column whose value is being generated by the sequence.
F. You use REUSE clause when creating a sequence to restart the sequence once it generates the maximum value defined for the sequence.