Some atoms of an element contain more neutrons or fewer neutrons than the most commonly found "version" of the atoms for that element. These "alternate versions" of the standard atom are called:

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

igneous rocks which formed by the crystallization of magma at the surface of the earth called extrusive rocks. they are characterized by fine-grained textures because the rapid cooling at or near the surface did not provide enough time for large crystals to grow.

looks like the answer is     c     to me!