What term defines the method of maintaining information over time in memory?

The correct term that defines the method of maintaining information over time in memory is storage. In the context of memory, storage refers to the process of preserving information so that it can be accessed and used later. This involves encoding information in a way that it can be stored in either short-term or long-term memory.

Retention relates more specifically to the ability to keep and hold onto the material that has been stored, but it does not encapsulate the entire process involved in keeping memory over time. Rehearsal refers to the process of actively working with information to encode it into memory, often by repeating it, but does not describe the actual retention or preservation of that information. Retrieval involves accessing and bringing to mind stored information but does not pertain to the initial storing process itself.

Thus, storage is the appropriate term, as it encompasses the overall mechanism of keeping information over time in memory.