The correct answer is Integumentary system.
The integumentary system includes skin and all its appendages (hair, scales, feathers, hooves, and nails) with the function to protect the body. It protects body from damage, from loss of water, from abrasion from outside and even protects the deeper tissues. On the other hand, integumentary system excretes wastes, regulates temperature, provides synthesis of vitamin D and many other things.
Karyotyping can give information on a persons sex and chromosomal disorders. It cannot give information on a persons trait's and how severe a disorder is.
I would go with B & D because they change over time and they can go extinct like those big octopus in the oceans, they are rare to see in my opinion because they can blend in with other things that keeps them away from danger.
Hey there what is your question?
I believe it's the temperature in the core