View the Exhibit and examine the structure of the CUSTOMERS table.

CUSTOMER_VU is a view based on CUSTOMERS_BR1 table which has the same structure as CUSTOMERS table.

CUSTOMERS needs to be updated to reflect the latest information about the customers.

What is the error in the following MERGE statement?

MERGE INTO customers c
USING customer_vu cv
ON (c.customer_id = cv.customer_id)
WHEN MATCHED THEN
UPDATE SET
c.customer_id = cv.customer_id,
c.cust_name = cv.cust_name,
c.cust_email = cv.cust_email,
c.income_level = cv.income_level
WHEN NOT MATCHED THEN
INSERT VALUES(cv.customer_id,cv.cust_name,cv.cust_email,cv.income_level)
WHERE cv.income_level >100000;

A) The INTO clause is misplaced in the command.
B) The WHERE clause cannot be used with INSERT.
C) CUSTOMER_VU cannot be used as a data source.
D) The CUSTOMER_ID column cannot be updated

answer：D