Which of the following is true of weighted-average process-costing? a) It does not represent the average cost of units when inputs prices fluctuates markedly from month to month. b) c) It facilitates period-to-period comparisons and hence is very useful in analyzing the performances of managers for different periods. It arrives at the same unit costs as arrived under FIFO method, but the computations are easier under weighted average process-costing. d) It calculates the cost per equivalent unit of all work done to date, regardless of the accounting period in which it was done.