Which one of the following best expresses the main point of the passage? A. The style of impressionist paintings has only an indirect relation to their subject matter. B. The approach to impressionism that is illustrated by Herbert's recent book is inadequate. C. The historical context of impressionist paintings is not relevant to their interpretation. D. impressionism emerged from a historical context of ideological conflict and change. E. Any adequate future interpretation of impressionism will have to come to terms with Herbert's view of this art movement.