A farmer has cash costs of S1.50/bu for his corn. The opportunity cost of his labor is S0.30/bu and the opportunity cost of his land (which he owns) is $0.40/bu. If he sells his corn for $2.50/bu, then his economic profits are:_______ A) $2.50/bu B) S1.00/bu C) S0.30/bu D) S0.70/bu E) can't tell based on the information given