Which of the following statements is true of process costing? a) In the period of rising prices, weighted-average process-costing method will result in higher operating income as compared to FIFO process-costing method. b) The operating income and the tax payments of a company are not affected by the method of process-costing being followed by the company. c) In the period of rising prices, weighted-average process-costing method will result in lower cost of goods sold as compared to FIFO process-costing method. d) In a period of falling prices, weighted-average process-costing method will increase tax payments as compared to FlFO processcosting method