4 ) Mad Dog fence company expects to sell an average of 30 fences p / month from January through December . Each fence sells for $1000 . The cost of materials is $250 per fence . The cost of labor is $350 per fence . Expert are paid in the month they are incurred . What is Mad dog's budgeted contribution margin each month ? A. $6, 000 B. $30, 000 C . $18 , 000 D. $12, 000