Digging deeper: Climate scientists are predicting that Earth's global average temperature could rise 4 degrees C (-7 degrees F) by 2100 if greenhouse gas concentrations in the atmosphere continue to rise at the current rate. How do you think this would impact the Greenland Ice Sheet's mass balance and global sea level? Why?

yes, because even though a theory has a  lot of evidence to support it, it is not always true

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