The answer is: Plastic
Plastic is the result of the addition polymerization of poly(alkenes). Thus plastic is a synthetic organic material.
Hope it helped!
Your question looks a bit incomplete as you have the same contents in options a) and d). According to your list, I can't see the correct answer, but I can give you one.The difference between the potential energy of the products of the potential energy of the reactants is equal to the enthalpy of the reaction.
Weathering would be chemical because it's more natural than physical