10 . Individual Problems 6-3 An end-of-aisle price promotion changes the price elasticity of a good from -2 to -3. Suppose the normal price is $12, which equates marginal revenue with marginal cost at the Initial elasticity of -2. What should the promotional price be when the elasticity changes to -3? (Hint: In other words, what price will equate marginal revenue and marginal cost?) O $9.00 O $5.40 O $6.30 O $7.20