3) ( 50 points) A purchasing agent for a particular type of silicon wafer used in the production of semiconductors must decide among two sources to meet the need of 20,000 wafers annually. Source A will sell the silicon wafers for $3.00 per wafer while it charges $100 shipping fee per order. Source B will sell the wafers for $2.50 each but will charge $500 flat fee per order plus $0.25 per unit shipping fee. D=20000 Assume a 20 percent annual interest rate for holding cost calculations. CA=3 \$per uint CB=2.5$ a) Determine the optimal order size for each option SA=100$ peorder SB=500 b) Which source should be used to procure the silicon wafers? H=0.2 H=0 e