Indicate the nature of each of the situations described below using the following three-letter code. CODE DESCRIPTION CPR: Change in principle reported retrospectively CPP: Change in principle reported prospectively CES: Change in estimate CRE: Change in reporting entity PPA: Prior period adjustment required Technological advance that renders worthless a patent with an unamortized cost of $45,000. Change from LIFO inventory costing to average inventory costing. Including in the consolidated financial statements a subsidiary acquired several years earlier that was appropriately not included in previous years. Change from FIFO inventory method to LIFO. Pension plan assets for a defined benefit pension plan achieving a rate of return in excess of the amount anticipated. Change from the pay-as-you-go method to estimating warranty expense in the period the related product is sold. Change from declining balance depreciation to straight-line. Change from determining lower of cost or market for inventories by the individual item approach to the aggregate approach. Settling a lawsuit for less than the amount accrued previously as a loss contingency. Change in the estimated useful life of office equipment