Through heat and pressure
A, is the correct answer.
The core is the densest because it is packed with SO much pressure that makes the molecules of nickel and iron(Elements of the core) immovable.
Answer:
Type O
Explanation:
Type O can donate red blood cells to anybody. It's the universal donor. Group AB can donate to other AB's but can receive from all others.
D all of these create a magnetic field. let me know if you want me to explain.