Answer:
The firm's total costs are $3,000 ($2,000 explicit costs + $1,000 implicit costs), and its revenue is $5,000. Therefore, the firm's accounting profit is $2,000 ($5,000 - $3,000). However, to calculate the economic profit, we need to subtract the opportunity cost of the resources used, including the implicit costs. Since the implicit costs are already included in the total costs, the economic profit is zero.
Therefore, the firm is earning a positive accounting profit of $2,000, but zero economic profit. The correct answer is "positive accounting profit of $2,000".