A. To remove excess Heat from the body
Answer
Just think critically about why (if you were an egg laying species), having a fetus/baby develop inside of you would be advantageous.
For one, eggs are much less protected from outside factors such as predators, temperature, etc than live birthed creatures. Live birth provides protection inside the mothers body from things such as heat, cold, moisture, predatory animals, etc. An egg laying animal must keep its eggs at a perfect temperature and check to make sure no other animal has eaten them.
Persipitation and geographic layout
Solid i believe. hope this helps
Heart is made up of Cardiac muscle