What rule in the Code of Chivalry, did Sir Gawain break and cause the Green Knight to mock him?

Which options most accurately assess the impact of transportation improvements (e. g., railroads, canals, steamboats, transcontinental railroad) on the settlement of the west? ***(select all that apply.)*** a. they led to an increase in population density. b. they made it easier to travel long distances. c. they in establishing towns. d. they led to the development of the fur trade. e. they allowed for international travel.