Determine the missing amounts. Unit Selling Price Unit Contribution Contribution Variable Margin per Ratio Costs Unit [b] $360 3096 [a] LLLLLL Select one: a. [a] = 500; [b] = 0.80; Ob. [a] = 350; [b] = 0.70; C. [a] = 1200; [b] = 840; d. [a] = 90; [b] = 0.36