Which Is NOT a Disadvantage of the Weighted Average Costing

Which is NOT a disadvantage of the weighted average costing assumption in process costing?

A) There is a possibility of errors when input costs are changing significantly from one period to the next.
B) The cumulative effect of an error might produce a significant distortion in the cost of the final product.
C) The performance of the current period is combined with the performance of the current period making it difficult to compare costs between periods.
D) Unit costs are simpler to calculate.