Correct option is C
The correct order to form a coherent paragraph is (c) CDBA.
Sentence C is the introductory statement. It sets the context by mentioning Ruskin's belief about the five intellectual professions in a civilized society.
Following this introduction, Sentence D logically follows as it talks about the expectations of honesty from the persons belonging to these professions, directly relating to the professions mentioned in Sentence C.
Next, Sentence B provides a specific example (the merchant) and elaborates on what honesty means in the context of one of these professions, thus naturally extending the idea introduced in Sentence D.
Finally, Sentence A introduces a question or a problem ('what social pressure can be exercised against a dishonest person'), which is a deeper exploration of the theme of honesty in professional life. This question is a logical follow-up to the expectations and examples provided in the preceding sentences.