Look forward and never hold your breath
Start with your producers, or plants (grasses, flowers, etc.). Then your 1st level consumers (herbivores), like grasshoppers, mice, etc. Then your second level producers (carnivores and omnivores) that eat the herbivores (like birds). And keep going, knowing each of the levels get eaten by each other. 10% of energy is transferred in each level. An example might be...
Grass > Mice > Hawk > Vulture
Your answer is B.
testosterone is male
endorphins are for happiness i think? but they're not female specific so the only answer without either of those is B
