Directly The immune system is designed to defend the body against foreign or dangerous invaders. Such invaders include
Microorganisms (commonly called germs, such as bacteria, viruses, and fungi)
Parasites (such as worms)
Cancer cells
Transplanted organs and tissues
To defend the body against these invaders, the immune system must be able to distinguish between
What belongs in the body (self)
What does not (nonself or foreign) normal immune response consists of the following:
Recognizing a potentially harmful foreign antigen
Activating and mobilizing forces to defend against it
Attacking it
Controlling and ending the attack
If the immune system malfunctions and mistakes self for nonself, it may attack the body’s own tissues, causing an autoimmune disorder, such as rheumatoid arthritis, Hashimoto thyroiditis, or systemic lupus erythematosus (lupus).
<span>Because of the difference in materials and the compression of gravity at depth, the inner core is the highest density. The lowest is the crust which is basically floating on the mantle. While no one has drilled that far, the basic assumption from magnetism and pieces of other planets delivered as meteors is that the inner material is iron, nickel and other heavy magnetic elements along with heavy radioactive elements.
The final answer to your question is C. core.
I am hoping that this answer has satisfied your query and it will be able to help you in your endeavor, and if you would like, feel free to ask another question.
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The main source of heat energy in the earth's inner core is radioactive decay, and the radiogenic heat producted by the radiogenic decay of isotopes in the mantle and crsut. I hope this helped