Which of the Following Statements Accurately Brings Out the Difference

Which of the following statements accurately brings out the difference between economies of scale and learning effects?

A) While there are no diseconomies to learning, there are diseconomies to scale.
B) Economies of scale occur over time, whereas learning effects are captured at one point in time.
C) Firms experience economies of scale when output increases, and learning effects when output decreases.
D) Economies of scale reduce cost per unit, learning effects increase cost per unit.