Production estimates for August are as follows: Estimated inventory (units), August 1 Desired inventory (units), August 31 Expected sales volume (units), August 12,000 9,000 75,000 For each unit produced, the direct materials requirements are as follows: Direct material A ($5 per lb.) Direct material B ($15 per lb.) 3 lbs. 1/2 lb. The total direct materials purchases of materials A and B required for August production is Oa. $1,080,000 for A: $540,000 for B Ob. $1.125.000 for A: $562,500 for B Oc. $1,170,000 for A $585.000 for B Od. $1.260,000 for A: $630,000 for B