Interlace, Inc. produces and a unique soda. The company cannot price discriminate. The figure above shows Interlace's demand curve, marginal revenue curve, and marginal cost curve. The quantity of soda Interlace Inc. will choose to produce is ________ because when this quantity is produced, ________.
选项：

A: efficient; marginal social benefit exceeds marginal social cost
B: efficient; marginal social benefit equals marginal social cost
C: not efficient; marginal social benefit exceeds marginal social cost
D: not efficient; marginal social benefit equals marginal social cost