Suppose that a business incurred implicit costs of $400,000 and explicit costs of $3 million in a specific year. If the firm sold 100,000 units of its output at $40 per unit, its accounting:

A: Profits were $600,000 and its economic profits were $1,000,000.

B: Profits were $3,600,000 and its economic profits were $600,000.

C: Losses were $600,000 and its economic losses were zero.

D: Profits were $1,000,000 and its economic profits were $600,000.