When a firm is experiencing increasing marginal costs,it implies​

A) ​A constant marginal productivity
B) decreasing average costs
C) decreasing marginal productivity
D) ​increasing marginal productivity

Increasing marginal costs typically indicate decreasing marginal productivity. As the firm increases production, it may need to hire more workers or invest in other inputs, but each additional unit of input may yield less output, leading to an increase in marginal cost. This can often result in a U-shaped average cost curve, where costs are initially decreasing but then start to increase as output expands.