If Moroccan shepherds allow their livestock to over-graze their land, the plants can no longer protect the fertile top soil from being removed by wind and rain. What can turn fertile soil into barren, arid land.

the members of alcoholic anonymous aren't required to disclose their last names.

out of the choices i'd say d the ability to set goals, mainly because to desire to continue you need motivation but it isn't motivation in that part, but setting goals means you have an endgame and you want to reach it which sums up motivation.