Please help! What gave rise to the slave trade?

a. The lack of a skilled labor force in the Americas and the decline of the West African population caused residents to seek a living elsewhere.
b. The shipment of gold from the Americas to Europe caused plantation owners to seek inexpensive laborers.
c. The death of many American Indians to disease and the planting of labor-intensive crops.
d. The global expansion of the spice trade and the rise of Christianity in the Americas.

(A)

Explanation:

well its that the americans and all the other continents were less skilled and more lazzy

the completion of the erie canal spurred the first great westward movement of american settlers, gave access to the rich land and resources west of the appalachians and made new york the preeminent commercial city in the united states.

answer: the time zones used to be whatever the local authority wanted them to be. one town might have 6am whenever the sun came up and another town had 6am 10 minutes later.  

the trains had a hard time when their orders said to be at a certain point at 6am.  

6am, but who's 6am.  

the railroads got together and set the time zones more or less along the longitude lines across the country.

explanation: