Кто как считает, А или D ?

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You are a database developer for an insurance company.
Information about the company's insurance policies is stored
in a SQL Server 2000 database. You create a table named policy
for this database by using the script shown below:

CREATE TABLE Policy
(
PolicyNumber int NOT NULL DEFAULT (0),
InsuredLastName char (30) NOT NULL,
InsuredFirstName char (20) NOT NULL,
InsuredBirthDate dattime NOT NULL,
PolicyDate datetime NOT NULL,
FaceAmount money NOT NULL,
CONSTRAINT PK_Policy PRIMARY KEY (PolicyNumber)
)

Each time the company sells a new policy, the policy must be assigned a
unique policy number. The database must assign a new policy number when
a new policy is entered. What should you do?

A. Create an INSTEAD OF INSERT trigger to generate a new policy number,
and include the policy number in the data instead into the table.
B. Create an INSTEAD OF UPDATE trigger to generate a new policy number,
and include the policy number in the data inserted into the table.
C. Create an AFTER UPDATE trigger to generate a new policy number,
and include the policy number in the data inserted into the table.
D. Replace the DEFAULT constraint with a AFTER INSERT trigger that generates
a new policy number and includes the policy number in the data inserted into
the table.

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