There is speculation that the mayor will hire a new staff member this week. But before every prior hiring of a new staff member, the mayor has met with the city' s budget director and finance advisor. No meetings between the mayor and the city' s budget director and finance advisor have occurred or are planned. Ttherefore, the speculation is more than likely baseless. Which one of the following most accurately expresses a principle of reasoning employed by the argument in the paragraph above? ['A hypothesis can be true even when it is not supported by available data.', 'If two assertions are known to be incompatible with each other and if one assertion is known to be false, it cannot be deduced from known facts that the other assertion is true.', 'Even if history suggests that an event was caused by a certain set of circumstances, it would be a mistake to assume that the event will only reoccur under the same set of circumstance as it occurred under before.', 'A conjecture is undermined when certain events do not occur that would be expected to occur if the conjecture were true.']