The hypothalamus is a part of the central nervous system that is directly linked to the pituitary gland and regulates its activity.
The pituitary gland is key in regulating the whole endocrine system because it secretes hormones that control the releasing of hormones in other glands such as the adrenal glands, the gonads etc.
The hypothalamus excretes releasing hormones which travel to the pituitary and start the excretion of another set of hormones that travel to other glands starting the production of their own hormones.
This forms a delicate system which has a moving balance and responds to external stimuli through the connection the hypothalamus has with other parts of the brain which process information that comes from the external and internal receptors ( such as heat, hunger, emotional state etc.).
Explanation:
if you were trying to find the function of something it you would mainly think of roles, jobs, responsibilities, chores etc, where as if you were trying to find the structure it would be how something is made up or its form.
for example the srtucture of a plant, meaning its form or how it grew, its function depends on what type of plant, if it were just a regular plant or leaf, the stomata, cell wall, cell membrane, nucleus, chloroplasts, chlorophyll inside the chloroplasts, mitochondria, cytoplasm, would be requied to do their funtions i.e their jobs to keep the plant/leaf alive
I think A and B. And maybe C?
Muhammad Divided the first Islam empire