Please choose the correct ending to complete the given sentence: Computers and Electronics: [header] How to restore a macbook pro [title] Back up any files you want saved to an external hard drive or online cloud storage system. [step] Restoring your macbook pro will wipe and erase all the data from your computer's hard drive. [title] Power off your macbook and connect it to a power source.

Ending1: [step] Connect one end of the macbook pro to the power socket on your power cord and the other end to your pc. You'll find the power plug-in switch next to your pc. Ending2: [step] This will prevent your computer from shutting down and interfering with the restoration process. [title] Power on your macbook pro and wait for the apple startup sound. Ending3: [step] Do this by removing any built-in peripherals. [title] Locate and unplug the computer from the power source. Ending4: [step] To close off macbook's hardware for later on, connect its system to electrical outlet. [title] Shut down all programs in your macbook pro.

Answer format: ending1/ending2/ending3/ending4