What type of memory can retain its data even during a power failure?

Nonvolatile memory is specifically designed to retain its data even when power is lost. This characteristic is essential in various applications where data integrity during power outages is critical, such as in embedded systems and storage devices. Nonvolatile memory includes types like flash memory and magnetic storage, which are capable of holding information without needing a continuous power supply.

Volatile memory, in contrast, loses its data when power is removed; this type is often used for temporary storage and system operations, such as RAM. Read-only memory (ROM) is a subset of nonvolatile memory that typically contains essential data and instructions that are not lost when power is off. Cache memory, while fast and crucial for processor performance, is also volatile and does not retain data when power is cut.

Thus, the distinction of retaining data during power failures firmly aligns with the characteristics of nonvolatile memory, making it the correct choice in this context.