What Was the Impact of the Introduction of American Crops

What was the impact of the introduction of American crops into Europe?

A) The introduction of the potato led to major population growth in Europe.
B) Fungi introduced to Europe, along with American crops, led to a severe decrease in agricultural productivity.
C) Although American crops were introduced around the world by European traders, they were not adopted in Europe itself.
D) Plantation agriculture fueled by slave labor became the norm in European agricultural systems.