Profit center responsibility reporting for a service company following quarterly income and expense accounts were provided from the trial balance as of December 31 : The following additional information has been gathered: 2. What is the profit margin of each region? Round to one decimal place. Identify the most successful region according to the profit margin. 3. What would you include in a recommendation to the CEO for a better method for evaluating the performance of the regions? a. The method used to evaluate the performance of the regions should be reevaluated. b. A better regional performance measure would be the return on investment (operating income divided by regional assets). c. A better regional performance measure would be the residual income (operating income less a minimal return on regional assets). d. None of these choices would be included. e. All of these choices (a, b \& c) would be included