Correct Answer:
A
A primary key is a unique identifier for each record in a database table. It must be unique and not null across all rows. In this table, the field ID is the only column that uniquely identifies each row and does not repeat.
''A primary key is a field (or a set of fields) that uniquely identifies a record in a table. It ensures that each record can be uniquely retrieved.'' --- CompTIA ITF+ Official Study Guide
Analysis of other options:
Month, Day, Year, and Name can have duplicate values across multiple records and therefore do not serve as unique identifiers.
Correct answer: A
The ID field contains unique values for each record and is typically used as a primary key in a database. A primary key uniquely identifies each row in a table.
Month, Day, Year, and Name may have duplicates and do not guarantee uniqueness.
