Defining characteristic of the American enlightenment

Although there is no consensus about the exact span of time that corresponds to the American Enlightenment, it is safe to say that it occurred during the eighteenth century among thinkers in British North America and the early United States and was inspired by the ideas of the British and French Enlightenments.  Based on the metaphor of bringing light to the Dark Age, the Age of the Enlightenment (Siècle des lumières in French and Aufklärung in German) shifted allegiances away from absolute authority, whether religious or political, to more skeptical and optimistic attitudes about human nature, religion and politics.  In the American context, thinkers such as Thomas Paine, James Madison, Thomas Jefferson, John Adams and Benjamin Franklin invented and adopted revolutionary ideas about scientific rationality, religious toleration and experimental political organization—ideas that would have far-reaching effects on the development of the fledgling nation.  Some coupled science and religion in the notion of deism; others asserted the natural rights of man in the anti-authoritarian doctrine of liberalism; and still others touted the importance of cultivating virtue, enlightened leadership and community in early forms of republican thinking. At least six ideas came to punctuate American Enlightenment thinking: deism, liberalism, republicanism, conservatism, toleration and scientific progress. Many of these were shared with European Enlightenment thinkers, but in some instances took a uniquely American form.

that would be the steamboat because none of the other things are forms of transportation

d is the right answer