Answer:
Firmware is typically contained in ROM (Read-Only Memory).
ROM is a non-volatile type of memory that retains its content even when power is turned off. Firmware, which is a type of software that is permanently programmed into a hardware device, is often stored in ROM. Unlike Random Access Memory (RAM), which is volatile and loses its content upon power loss, ROM retains its data and allows the firmware to be executed whenever the device is turned on.
Therefore, the correct answer is c. ROM.