What is the formula managers use to calculate a percentage variance when comparing last year's profits to this year's profits? Select one: a. (Profits This Year Profits Last Year) Profits Last Year = % Variance b. (Profits Last Year Profits This Year) Profits This Year = % Variance c. (Profits This Year Profits Last Year) x Profits Last Year = % Variance d. (Profits Last Year Profits This Year) x Profits This Year = % Variance