Final answer:
The correct answer is option d. Mid-quarter; Half-year; 50%.
Step-by-step explanation:
The correct answer to the question is option d. Mid-quarter; Half-year; 50%.
The (1)-(2) convention is a method used for determining depreciation expense for assets purchased in a given year. The Mid-quarter convention is used when more than 40% of the total cost of all tangible personal property is placed in service during the fourth quarter of the year. The Half-year convention is used for assets placed in service in the first half of the year. Therefore, the correct combination is Mid-quarter and Half-year, with a threshold of 50%.