It's basically when there were bans against alcohol consumption and production. so wet=alcohol and dry=no alcohol
Formation and Early History of the NHL (1917–41) The National Hockey League (NHL) was established in Montréal, Québec, on 26 November 1917. ... The Ottawa Senators dominated the 1920s, with six league titles and four Stanley Cup victories; however, the team folded in 1934.
I thins is B because of the Cuban came to saint area