Aircraft Cabin Lights Off

Another flying session last weekend.

After years of traveling by air, only recently I started to wonder why the cabin lights are off during take off/landing.

Of course just Google it & you'll get the answer in an instance. But how many of us really have the luxury & time to do that.

Here are some of the plausible answers:
(Bear in mind that take off & landing are stages of flight when aircraft are most prone to accidents & emergencies).

A) To preserve electrical power to run the important stuff.

B) The light may affect the cockpit, and the pilot may get a glare in the screen, thinking it is another airplane.

C) Dimming the cabin will adjust passenger's eyes to the amount of light outside, so it won't take time for the passenger's eyes to adjust in the event of an emergency.

D) So you can't see your life flashing before your eyes. Hehe... Shit.

Which one it's gonna be?