Final answer:
The correct answer is C) Third Normal Form (3NF), which states that a table is in 3NF if it is already in 2NF and there are no non-key attributes determined by another non-key attribute.
Step-by-step explanation:
Understanding Third Normal Form (3NF) in Database Design
To classify the normal form of a relation in database design, one needs to understand the definitions of different normal forms. In regard to the options provided:
- A) First normal form (1NF) requires that there are no duplicate columns in a table and that each cell is atomic, meaning that there are no repeating groups or arrays within a cell.
- B) Second normal form (2NF) is achieved when a table is in 1NF and all non-key attributes are fully functionally dependent on the primary key.
- C) Third normal form (3NF) goes a step further; a table is in 3NF if it is in 2NF and if all the non-key attributes are not only fully dependent on the primary key but are also non-transitively dependent on the primary key. This means that there should be no dependencies of non-key attributes on other non-key attributes.
- D) Fourth normal form (4NF) involves multi-valued dependencies and is beyond the scope of this question.
From the definitions above, the correct answer to the student's question is C) Third Normal Form (3NF), as it specifically defines that a relation in 3NF must be in 2NF and that there should be no transitive dependencies among non-key attributes.