Production estimates for August are as follows: Estimated inventory (units), August 1 12,000 Desired inventory (units), August 31 9,000 Expected sales volume (units), August 75,000 For each unit produced, the direct materials requirements are as follows: Direct material A ($5 per lb.) 3 lbs. Direct material B ($15 per 1b.) 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: 5562.500 for B Oc. $1.170.000 for Ar $585,000 for B d. $1.260.000 for AI $630,000 for B