Detailed Answer
Answer (A) is correct. Learning curves reflect the increased rate at which people perform as they gain experience at a new task. Because the time to perform the task becomes progressively shorter in the early stages of a new activity, the direct labor costs involved decline. The curve is often expressed as a percentage reduction in time for each doubling of cumulative production. Two models are in common use. One assumes that the cumulative average time per unit declines by a constant percentage each time duction doubles. The other assumes that the time required for the last unit declines by a constant percentage when cumulative production doubles.