Production estimates for July are as follows: Estimated inventory (units), July 1 8,500 Desired inventory (units), July 31 10,500 Expected sales volume (units), July 76,000 For each unit produced, the direct materials requirements are as follows: Direct material A ($5 per lb.) 3 lbs. Direct material B ($18 per lb.) 1/2 lb. The total direct materials purchases of materials A and B (assuming no beginning or ending material inventory) required for July production is

a. $1,080,000 for A; $648,000 for B

b. $1,170,000 for A; $702,000 for B

c. $1,125,000 for A; $675,000 for B

d. $1,080,000 for A; $1,296,000 for B