The correct answer is C.
OBJ-3.5: The display option is currently set to auto-brightness (this is acceptable), lock after 30 minutes (this is not recommended), and night mode disabled (this is optional based on the user’s preference). The display setting of a lock after 30 minutes will keep the smartphone’s display on for 30 betweens after the phone is last used or touched by the user. This will waste a lot of battery power and cause the device to become warm to the touch. The display is one of the largest users of battery power on a smartphone. This setting should be set to 1-3 minutes to help extend the device’s battery life.