Final answer:
Permit records should be retrievable by date of application, permit number, or street address. These methods provide efficient access to specific permits or permit data organized chronologically or by location.
Step-by-step explanation:
When organizing permit records, the system should enable retrieval of permit files in an efficient and logical manner. Common methods to key a retrieval system include using the date of application, the permit number, or the street address associated with the permit. Organizing by the applicant's age would be less conventional and practical for most permit systems since it's not typically relevant information for a permit.
Retrieving by date of application would be useful for chronological tracking, while the permit number is an identifier that would likely allow for quick access to a specific permit. On the other hand, organizing by street address could be helpful for understanding permits within a particular area or for municipal planning purposes.