Georgia uses the high-low method of estimating costs. Georgia had total costs of $32,775 at its lowest level of activity, when 5,300 units were sold. When, at its highest level of activity, sales equaled 21,400 units, total costs were $85,100. Georgia would estimate variable cost per unit as

A. $3.25

B. $4.41

C. $3.98

D. $6.18