Thanks for the question! So we’re being asked here for the best interpretation of “curious blind spot” in lines 2-3. Remember, when we get a line reference, go to those lines and read above and below to understand the full context. For this one, it’s good to understand the passage as a whole. The author isn’t a huge fan of Watteau’s, or at least doesn’t think that he should be considered representative of French life in the early 1700s. And that’s what (B) says, that other writers aren’t aware of an obvious discrepancy (that Watteau wasn’t really French and only saw certain aspects of France, for example).
Hope this helps! Feel free to ask any other questions that you might have.
