Which technique should be used to load the data most efficiently?

You need to load information about new customers from the NEW_CUST table into the
tables CUST and CUST_SPECIAL If a new customer has a credit limit greater than
10,000, then the details have to be inserted into CUST_SPECIAL All new customer
details have to be inserted into the CUST table. Which technique should be used to load
the data most efficiently?

A.
external table

B.
the MERGE command

C.
the multitable INSERT command

D.
INSERT using WITH CHECK OPTION