I think it's 420,000 kcal, because 10% of energy is lost as you move up each trophic level. To find what you started with you would multiply by 10 instead of dividing by 10. You have to multiply by 10 twice, because of the primary consumers and producers.
Option 1 is the correct answer
Been a bit since I learned this but I believe the answer is B.
Hope this helps.
Evolution has led giraffes to have very long necks. Trees in the savannah have less leaves on bottom branches because of other animals. For the giraffe to survive, their necks slowly became longer as they could eat more leaves from upper/top branches. If they had not evolved longer necks, they would not exist today.