9. Which one of the following is an assumption on which the ornithologist’s reasoning depends?
(A) Modern tree-dwelling birds are the direct descendants of Archeopteryx.
(B) Archeopteryx made use of the curvature of its claws.
(C) There have never been tree-dwelling birds without curved claws.
(D) Archeopteryx was in fact the earliest birdlike creature.
(E) The curvature of the claws is the only available evidence for the laim that Archeopteryx was tree-dwelling.
10. There are rumors that the Premier will reshuffle the cabinet this week. However, every previous reshuffle that the Premier has made was preceded by meetings between the Premier and senior cabinet members. No such meetings have occurred or are planned. Therefore the rumors are most likely false.
Which one of the following most accurately expresses a principle of reasoning employed by the argument?
(B) A hypothesis is undermined when a state of affairs does not obtain that would be expected to obtain if the hypothesis were true.