1.20 South Africa trades in commodities... (4 Marks) a) For political pressure b) Due to its absolute advantage in producing commodities c) Due to its comparative advantage in producing commodities d) To invest in the global economy 1.21 GDP can be calculated by all of the following methods except... (4 Marks) a) Adding up the spending on goods and services by business, government, households, and foreigners, and subtracting imports. b) Adding up the "value added" at every stage of production in the economy. c) Adding up all of the receipts of households, government, and business. d) Adding up all income and expenses by consumers and businesses.