the correct answer you are looking for would be letter B. formation of geological layers
hope this helps :)
Answer:
cell membrane
Explanation
It's the outer living boundary of animal cells. It's made of lipid and protein. Plasma Membrane is a mosaic of phospholipids, cholesterol, and proteins, the proteins in plasma membrane regulates the coming/going of substances into/out of the cell.
That they both had nearly the same hypothesis