Astrologer: Although some scientists have claimed that there is no correlation between people' s astrological signs and their personality types, this claim is scientifically unjustified. Since science does not have precise criteria for distinguishing one personality type from another, scientific studies cannot be used to disprove a correlation between personality type and any other phenomenon. Which one of the following most accurately describes the role played in the astrologer's argument by the statement that scientific studies cannot be used to disprove a correlation between personality type and any other phenomenon? ['It is a claim offered as support for a conclusion that is in turn offered as support for the overall conclusion drawn in the argument.', 'It summarizes a position that the argument as a whole is directed toward discrediting.', 'It is a conclusion for which support is offered and that in turn is offered as support for the overall conclusion drawn in the argument.', 'It provides a specific instance of the general principle that the argument as a whole is directed toward establishing.']