The black swan is an example of negative evidence that disproves the theory that all swans are white. We want something analogous: an example of negative evidence that helped to disprove Newton’s theory. Mercury is a great example. Mercury’s orbit didn’t match what Newton’s theory predicted, which made Mercury itself negative evidence against Newton’s theory. This ultimately led to the disproving of Newton’s theory. So Mercury is analogous to the black swan.

The black swan is an example of negative evidence that disproves the theory that all swans are white. We want something analogous: an example of negative evidence that helped to disprove Newton’s theory. But Uranus was positive evidence in support of Newton’s theory. (Once Neptune was accounted for, Uranus’s orbit perfectly matched what Newton’s theory predicted.)

The black swan is an example of negative evidence that disproves the theory that all swans are white. We want something analogous: an example of negative evidence that helped to disprove Newton’s theory. But Neptune wasn’t negative evidence against Newton’s theory. To the contrary, Neptune saved Newton’s theory by offering an alternative hypothesis for why Newton’s theory initially failed to predict the orbit of Uranus. (It wasn’t that Newton’s theory was wrong; it was just that scientists overlooked the existence of Neptune. Once they accounted for Neptune, their observations matched Newton’s theories.)

Venus isn’t mentioned in passage B. We’re looking for something in mentioned in passage B that’s analogous to the black swan in passage A.

The black swan is an example of negative evidence that disproves the theory that all swans are white. We want something analogous: an example of negative evidence that helped to disprove Newton’s theory. But the sun didn’t help to disprove Newton’s theory.