What type of storage requires power to retain data?

Volatile storage is the correct choice because it refers to memory that requires a continuous power supply to retain data. When the power is turned off, any information stored in volatile storage is lost. This includes types of memory such as RAM (Random Access Memory), which is widely used in computers to store data that's actively being processed.

In contrast, non-volatile storage retains data even without power, making it suitable for long-term data storage. Magnetic storage, such as hard drives, and optical storage, like CDs and DVDs, are types of non-volatile storage. Both of these options keep their data intact without needing power, which is why they don't fit the requirement of needing power to retain data.