The right answer is the chloroplast.
Autotrophic species must stock up on food in order to have energy at all times.
Plants, for example, through their chloroplasts make sugar with the energy of sunlight and from soil water and carbon dioxide from the air. This sugar synthesis using light is photosynthesis.
When the bird is decomposed, more energy is transfered since its's bigger than a fly, a spider and the amount of fruit a fly can eat.
Hope it helped,
BioTeacher101
Pretty sure that the endocrine system is represented by the diagram
So the answer is endocrine