According to empiricists, though the kind of information provided by analytic a priori propositions is indubitable, it is not very useful in expanding our knowledge about the world, because: Select one: a. any information provided by such propositions is ultimately based on someone's personal experience. b. such propositions are true (or false) by definition and do not describe any facts about the world. c. the world is nothing other than what we experience it to be. d. such propositions are concerned with the world as it is in itself, not with how we experience the world.