David is paid on a graduated commission scale at Nooter Company. He receives 2% commission on the first $20,000, 6% on sales from $20,000 to $70,000. 8.5% commission on sales from $70,000 to $100,000, and 10% commission on sales over $100.000 David had sales of $82,000. His commission is: 

a). $4.420 

b). $4.240 

c). $6.200 

d). $8.200 

e). None of the answers