please answer all 4 multiple choice questions

A normal job-order costing system is a system that uses: actual costs for direct materials and estimated costs for direct labor and overhead. actual costs for direct materials and overhead, estimated costs for direct labor. estimated costs for direct materials, direct labor, and overhead. actual costs for direct materials and direct labor and estimated costs for overhead. Future costs that differ across alternatives are opportunity costs. relevant costs. variable costs. sunk costs. product costs. Choice of allocation base should be made based on: the relative size of the base. the base's relation to direct labor. the base's activity. whether the base actually drives the cost being allocated. Which of the following is preferred by managers when the risk of obsolescence is high? A short payback period A high opportunity cost A low accounting rate of return All of these None of these