Friction is the force that resists movement, and that's why oil is used as a lubricant and why ball bearings are used for machines that need to move with very little friction(i.e. bike wheels, roller skates, fidget spinners)
Answer B is too vague C will probably reduce efficiency greatly, but not specifically in a way that turns work into thermal energy. D is the same as C, except that it places the blame on the person using the machine, not the machine itself.
"The environmental change that occurs faster is definitely volcanic eruption. It may happen in an instant and destroy everything in its way, whereas the process of regrowth of forest after volcanic eruption is a slow one."
