Answer:
The correct answer is option d.
Explanation:
The 100th unit of output that the firm produces has a marginal revenue of $11 and a marginal cost of $10.
The profit to a firm is maximized when the marginal revenue earned and marginal cost incurred are equal.
When the firm is producing the 100th unit of output the marginal revenue is $1 higher than the marginal cost. This implies that the production of the 100th unit increases the firm's profit by $1.