NEED ASAP! Why do geologists think earths core contains mostly iron?

A. Other orbiting bodies contain more iron than earth's crust does.
B. The moon's crust contains far less iron than earth's crust.
C. The crust contains no nickel.
D. The crust contains a mixture of iron and silicon.

phylogenetic tree is the tree of life or evolution tree. it shows the different branches of evolution. the sequence goes like tissues - coelom - backbone - endoskeleton - segmentation

they deliver oxygen to the blood

b brown mice / white sand dunes

"do a testcross with a homozygous recessive plant."