Answer:
Keelboats have been used for exploration, such as during the Lewis and Clark Expedition, but were primarily used to transport cargo or settlers in the early 19th century. The process of moving a keelboat upriver was extremely difficult, though current dependent.The earliest keelboat seems to have been a skiff with a plank nailed the length of the bottom to make the boat easier to steer, but by about 1790 the keelboat had become a long narrow craft built on a keel and ribs, with a long cargo box amidships.
Explanation:
THe correct answer is a or b
