Shau's medical insurance policy includes a $100 deductible. Shaun is required to pay 20 percent of covered expenses in excess of the deductible, and his insurer will pay 80 percent of covered expenses in excess of the deductible. Shaun was hospitalized and his covered medical expenses were $8,100. How much of the $8,100 will be paid by the insurer?

A) $8,000

B) $8,100

C) $6,400

D) $6,480