A purchasing agent for a particular type of silicon wafer used in the production of semiconductors must decide among two sources.Source A will sell the silicon wafers for $$2\mathrm{.}50$ per wafer, independently of the number of wafers ordered.Source B accepts any order quantity, but sells the wafers for $$2\mathrm{.}55$ each for orders of up to $3,000$ wafers and $$2\mathrm{.}25$ each for the incremental amount ordered over $3,000$ wafers.Assume an order setup cost of $$100$ and annual requirement of $20,000$ wafers.Holding cost is $20\%$ of its purchasing cost per unit per year.Which source should be used? And what is the order size? What is the total cost of ownership? Let's assume that the order size has to be a multiple of $500,$ i$.$e$.,$ you can only order $500,1000,1500,2000,$ etc.