For each of the scenarios, please indicate whether there will be an increase or decrease in short-run aggregate supply or if there will be no change. a. The production of a new type of blade for combine harvesters, a tractor used to harvest crops, has allowed wheat farmers to increase productivity by 40%. b. The price of lumber, a commodity, rises drastically due to the effect of heavy winter weather in the American Northwest, where much of the world's lumber is grown. c. A major hurricane in the Gulf of Mexico destroys several oil rigs.