In the process of rolling down the hill was done to push aside trees and other stones that stood in the way.

The answer is d if you are on edgenuity. 

So  if  the sum of the enthalpies of the reactants is greater than the products, the  reaction  will be  exothermic.  if  the products side has a larger enthalpy, the  reaction  is  endothermic. you may wonder why  endothermic reactions, which soak up energy or enthalpy from the environment, even happen

Lol why dont you actually do the work instead of have people do it for you. jk i do it too lol

Iwould say the answer is d