The northern hemisphere is warmer in the summer than the winter because the northern hemisphere are pointing toward the sun. Because of this the rays hit us more directly making is hotter. So during the winter when the northern hemisphere is not pointing toward us, it makes is colder. It also depends on the tilt of the axis. When it is more direct it makes the temperature hotter.
I would say it's A because it sounds like the most important one.
Salutations!
What is the skull mainly composed of how many cranium?
The skull is composed of eight cranial bones (cranium). Cranial bone is the bone that protects the top part of the brain. If we are generally speaking, the skull consists of 22 bones.
Hope I helped (:
Have a great day!
Hope this helps!
Estrogen is made out of steroid hormones