Answer:
D) A giraffe's long tail
Step-by-step explanation:
I'm guessing this is the right choice because:
a. Migration is a survival instinct and doesn't particularly help with energy.
b. A polar bear's thick fur is to protect it from the cold and helps to warm the animal, but it doesn't supply energy.
c. A monkey's long tail is indeed useful for hanging from branch and climbing, yet they have four other limbs that aid in the same process and again, it doesn't neccessarily supply energy.
d. A giraffe's long neck is used to eat from trees since giraffes are herbivores and eat from tall trees, which counts as energy. This is because when the eaten it is later converted into protein to be used energy.
I hope this helps!