Answer:
a. a decrease in the marginal productivity of her remaining capital and an increase in the marginal productivity of her labor.
Step-by-step explanation:
Diminishing returns In economics is the decrease in the marginal (incremental) output of a production process as the amount of a single factor of production is incrementally increased, while the amounts of all other factors of production stay constant.
Due to the fire outbreak, the owner will continuously try to increase her manual effort (labor) into the business, which at a point will overwhelm her remaining capital, leading to the decrease in the marginal productivity of what's left of her capital.