Refer to the figure below. which shows marginal benefits (MB) and marginal cost (MC) of activity A If the decision maker is choosing 400 units of activity A.Based on the figure below, the "best estimate' of the optimal activity level is.. Total Benefit and Total Cost 15)Level of Total benefit Total cost of Net benefit Marginal Marginal activity of activity activity of activity benefit cost O $0.00 $0.00 $0.00 $16.00 $14.00 W N H $6.00 $24.00 $4.00 $40.00 $10.00 $48.00 $24.00 $30.00 $6.00 6 $32.00 $2.00 $52.00 $34.00