Anne: Halley' s Comet, now in a part of its orbit relatively far from the Sun, recently flared brightly enough to be seen by telescope. No comet has ever been observed to flare so far from the Sun before, so such a flare must be highly unusual. Sue: Nonsense. Usually no one bothers to try to observe comets when they are so far from the Sun. This flare was observed only because an observatory was tracking Halley' s Comet very carefully. Sue challenges Anne's reasoning by ["presenting evidence that directly contradicts Anne's evidence", 'offering an alternative explanation for the evidence Anne cites', "undermining some of Anne's evidence while agreeing with her conclusion", 'pointing out that Anne\'s use of the term "observed" is excessively vague']