Abe gaonwasion koi zinda hai ki nahi agar nahi to mai jaa rahi hu-_-​

all these collisions do one thing, and that thing is explained in the last option. when dusst, rocks and ice collide, they harden and form giant layers of rocks or hard ice.

d)   to harden materials to form different parts of earth’s layers

hope it ,

bioteacher101