A health care organization has one main hospital site and three satellite sites in rural areas. The filing system would be described as:

In the context of the described health care organization, a decentralized filing system is characterized by the distribution of information management across multiple locations. Since the organization operates one main hospital and three satellite sites, each location likely manages its own patient records and data independently. This arrangement allows for greater responsiveness to localized needs, as each site can maintain its records based on the specific services they provide and the patient populations they serve.

A decentralized system often results in the duplication of records or variations in record-keeping practices, as each site may have different policies or procedures. However, it is beneficial in scenarios where immediate access to information is critical, especially in rural settings where patients may not always access the main hospital.

In contrast, a centralized system would imply that all records and data management activities are funneled through one main location, which does not accurately reflect the setup of this organization with its multiple sites. The other choices, off-site storage and serial-unit, do not align with the structure presented. Off-site storage typically involves keeping records separate from the primary service locations, and serial-unit is a filing system method that organizes records by a sequence of unit numbers or identifiers, which doesn’t directly address the distribution aspect of the sites.