(Figure: Marginal Benefit I) Which of the Following Statements Is

Multiple Choice

(Figure: Marginal Benefit I) Which of the following statements is (are) TRUE? I. The external marginal benefit is $7.
II) The socially optimal price is $5.
III) At an output level of 5 units, the deadweight loss is $6.
IV) At 8 units of output, there is no private marginal benefit and social marginal benefit is $4.

A) III
B) II, III, and IV
C) I, II, and III
D) IV