Answer:
A. Earthquake
Explanation:
When plates slide past each other, the edges of these are earthquake zones. Earthquakes are formed but not volcanoes.
"Eukaryote" roughly translates as "truly nucleated" and refers to organisms with a membrane-bound nucleus.
Such membrane-bound organelles are thought to have arisen via the invagination of the cell's own plasma membrane.
Other organelles such as the mitochondria and the chloroplast are believed to have once existed as separate organisms, but which were engulfed by other cells, forming a symbiotic relationship.
I don't know, maybe because of the way we see animals. Not as our equal parts