Cellular organelles have different structures. Mitochondria, for example, possess highly folded inner membranes in addition to their outer membranes. Vacuoles, on the other hand, are only surrounded by a single-layer membrane; they do not have an inner membrane

the earth is thought to have been formed about 4.6 billion years ago by collisions from a cloud of hydrogen, helium, rock, ice and other materials. these were pulled together by gravity to form objects in and around earth like- asteroids and small early planets called planetesimals.

so, the best possible answer to this question will be option d- to harden materials to form different parts of earth’s layers

cytokinin is what stimulates cell division