Which two methods can you use to get the required result?

Examine the structure of the customers table:

CUSTNO is the primary key in the table. You want to find out if any customers’ details have been
entered more than once using different CUSTNO, by listing all the duplicate names.
Which two methods can you use to get the required result?

A.
Self-join

B.
Subquery

C.
Full outer-join with self-join

D.
Left outer-join with self-join

E.
Right outer-join with self-join

Explanation: