Which of the following file organizations requires primary Key?

A file organization that requires a primary key is the Indexed file organization. In this type of file organization, records are stored in an index, which is a separate data structure that allows for fast access to the records based on the value of the primary key. The primary key is a unique identifier for each record, and it is used to look up the record in the index. This allows for efficient and quick retrieval of records, which is important in many applications. So, having a primary key is essential in indexed file organization.