The lines on this map represent transportation routes of what product?
a) cattle
b) cotton
c) iron
d) steel

Cattle

Explanation:

These lines represent the transportation of cattle during the 19th century. The transportation of cattle received the name of "cattle drives." This was one of the most important economic activities of the age, particularly in the American West. The cattle drives are associated with other quintessential American images, such as the horse and the cowboy. Cattle drives significantly declined towards the end of the century due to overgrazing and the introduction of barbed wire.