Answer:
d
Explanation:
Mitochondria is the power house of the cell. It's where aerobic respiration happens and release of energy as ATP happens.
Endocrine signaling is hormone based signaling that travels through the blood stream. Many of the sensors and integrating sensors of the endocrine system are located in the brain. The brain barrier contributes to endocrine signalling, such that the brain barrier does not factor in with endocrine signalling. The answer is A
The answer is C. Population size