I'm at least 85% sure that the answer would be A, it seems like the most secure answer to give.
Okay so other ways to produce energy would be (just throwing out a few )
1 . Gum
2. Light (light wakes up your brain a proven fact)
3. Massage your ears (im serious it boost energy its proven)
4. Eat something whole grain
5. Listening to your favorite song
(Im serious for all these answers)
Hope I helped (:
B: Plessy v. Ferguson because at that time they belived in seperate but equal..which was not the case it was really unfair. So brought to the matter they sorted it out in the supreme court.