Assume that the market of apples is a perfectly competitive one. Using graphical illustration, evaluate the effect on the equilibrium price and quantity of apples if the following events occur. a) The price of fertilizer used in apples plantation increases. (5 marks) b) Consumers' incomes decrease because of recession. (5 marks) c) The price of pears (a substitute for consumers) falls. (5 marks) d) Consumers expect the price of apples to increase next week. (5 marks)