Answer:
C is the answer!
Step-by-step explanation:
A hard drive contains your operating system which can include your settings and preferences that you included in your device. But it mostly is a storage device so we know it WOULD NOT BE (B.
WOULD NOT BE D beacause powering it back on wouldnt do anything but bring you back to the start.
WOULD NOT BE A beacuse when taking out the battery then putting it back in would just be like turning it off then back on beacuse that just hold the power to a device.
IT WOULD BE C, C IS THE ANSWER beacuse a CMOS batttery contains the main system settings and also contains information so i think C would be the best answer for this choice.
Hope this helps!
xx <3