Synonym for refract could be bend,swing arch or something similar to those words.
Well without a description om shooting in the dark. But id assume that the answer is Trench Warfare. Since A- was around since contact with Native Americans and largely popular in North America. B- Only was used and discovered in WW2. And C- was used but was largely frowned upon and condemned by both sides.<span />
The Impact of the Erie Canal - Rochester
The Erie Canal was built from the Hudson River to Lake Erie. It improved the economy in some cities in New York such as Buffalo Lockport, and Rochester. It lead New York to industrialization. It decreased the cost of transporting goods.