Choose the correct answerAn attribute in a relation is a foreign key if the _______ key from another relation is used as an attribute in that relation .OptionsPrimaryCandidateSuperSub

An attribute in a relation is a foreign key if the _______ key from another relation is used as an attribute in that relation.

Options:

• Primary
• Candidate
• Super
• Sub

To determine the correct answer, we need to understand the concept of a foreign key in a relation. A foreign key is an attribute in a relation that references the primary key of another relation. It is used to establish a relationship between the two relations.

Now, let's analyze the options:

1. Primary: A primary key is a unique identifier for a relation. It is not used as an attribute in another relation, so it cannot be a foreign key.

2. Candidate: A candidate key is a set of attributes that can uniquely identify a tuple in a relation. Similar to the primary key, it is not used as an attribute in another relation, so it cannot be a foreign key.

3. Super: The term "super" does not directly relate to the concept of foreign keys in a relation. It is not a valid option.

4. Sub: The term "sub" does not directly relate to the concept of foreign keys in a relation. It is not a valid option.

Based on the analysis, the correct answer is "Primary."