Martinez Corp., which began operations in January 2020 , follows IFRS and is subject to a 30% income tax rate. In 2023 , the following events took place: 1. The company switched from the zero-profit method to the percentage-of-completion method of accounting for its long-term construction projects. This change was a result of experience with the project and improved ability to estimate the costs to completion and therefore the percentage complete. 2. Due to a change in maintenance policy, the estimated useful life of Martinez's fleet of trucks was lengthened. 3. It was discovered that a machine with an original cost of $224,000, residual value of $30,400, and useful life of 4 years was expensed in error on January 23, 2022, when it was acquired. This situation was discovered after preparing the 2023 adjusting entries but before calculating income tax expense and closing the accounts. Martinez uses straight-line depreciation and takes a full year of depreciation in the year of acquisition. The asset's cost had been appropriately added to the CCA class in 2022 before the CCA was calculated and claimed. 4. As a result of an inventory study early in 2023 after the accounts for 2022 had been closed, management decided that the weighted average cost formula would provide a more relevant presentation in the financial statements than the FIFO cost formula. In making the change to weighted average cost, Martinez determined the following: (a) Analyze each of the four 2023 events described above. For each event, identify the type of accounting change that has occurred, and indicate whether it should be accounted for with full retrospective application, partial retrospective application, or prospective application