18.The question below is based on the following total cost and total revenue schedule for the ABC Company: Output 1 2 3 4 5 6 Total Revenue $1,000 $2,000 $3,000 $4,000 $5,000 $6,000 Total Cost a. 1 and 2 units per period. O b. 2 and 3 units per period. O c. 3 and 4 units per period. O d. 4 and 5 units per period. O e. 5 and 6 units per period. $1,000 $1,500 $2,300 $3,300 $5,000 $7,000 18.To maximize profits, the firm should produce between