Final answer:
The retention period likely refers to the required length of time to keep certain types of records or documents, varying based on law, policy, or industry standards.
Step-by-step explanation:
The question seems to be referencing the retention period for certain types of records or documents, as it asks what the retention period is for individuals 18 years or older, with options ranging from 10 to 25 years. While the context is not explicitly stated, it likely pertains to legal, health, education, or business records.
Since no specific context is provided in the question to determine the correct answer and the provided information does not give enough details, it is not possible to confidently select the correct retention period. In practice, these periods could range between 10 and 20 years, but without additional information, one cannot be sure.