OE
The word “Although” indicates that the blank will convey something that contrasts with the main clause of the sentence, which says that “_________ number of painters lived” to an old age. Since the sentence also says that paints contained poisons, you need two words that mean something like surprising or surprisingly large. The correct answers, “a flabbergasting” and “a confounding” both mean surprising. Trap answers “incomprehensible” and “impossible” go too far—it’s interesting that many painters had long lives, but it’s not beyond all comprehension. “Dismaying” is incorrect because it isn’t upsetting that many painters lived long lives. Although apparently contradictory information might be “enlightening,” that word has no match and cannot be correct.
Answer: B,D