Control Total Total Costs Net Marginal Marginal Marginal Variable Benefits Benefits Benehit Cost Net Benefit 0 800 100 C 800 100 A 300 1200 700 200 500 2100 700 1400 600 E 200 2400 B 1100 300 -300 3500 2300 10 00 900 Which number is A equal to? Please enter a numercial value. For example, to enter "three thousand" you need to type in "3000")