Answer & Explanation

4 Answers
Verified Correct Answer

Option A

A row may exist without a related row; a nullable foreign key or separate association can represent the optional relationship depending on the model.
Additional Explanation
Correct implementation. Prefer parameterized queries in application code, validate affected rows for UPDATE/DELETE, and use transactions for related writes.
Sarkari Resultess
Editorial Answer 1
Verified

Option B

Every row must have two parents.
Additional Explanation
This option is incorrect for the stated requirement.
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Editorial Answer 2
Verified

Option C

All columns must be NOT NULL.
Additional Explanation
This option is incorrect for the stated requirement.
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Editorial Answer 3
Verified

Option D

The table cannot have a primary key.
Additional Explanation
This option is incorrect for the stated requirement.
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Editorial Answer 4