Where Is the Operating System of a Raspberry Pi Stored

Multiple Choice

Where is the operating system of a Raspberry Pi stored?

A) On the master device attached to the Raspberry Pi's IDE bus.
B) On a read only partition on the Raspberry Pi's firmware, next to the BIOS.
C) On a removable SD card which is put into the Raspberry Pi.
D) On a Linux extension module connected to the Raspberry Pi's GPIO pins.
E) On rewritable flash storage which is built into the Raspberry Pi.