The correct answer is D. Robert Fulton's contribution to the transportation revolution of the 1800s was the creation of the first safe, practical and commercially succesful steamboat.
Robert Fulton was an American engineer, entrepreneur and inventor, known for developing the first steamboat, which became a commercial success.
At the end of 1803, Robert Fulton launched to the Seine a ship whose propeller was a paddle wheel, moved by a steam engin. But it was badly received in France, and Fulton continued his experiments in the United States. In 1807 he launched his steamboat to sail the 240 km that separate New York from Albany by crossing the Hudson River. With this same boat, the first regular steam service would be established. This steamboat had some wheels with paddles on both sides of the hull, a design that for a time extended a lot. This type of steamboat would be very successful in river navigation, since they needed little draft, although as an inconvenience they considerably increase the width of the ships.