Which of these was a negative effect of columbia exchange ?
a. the introduction of the potato to europe
b. the introduction of coffee to south america
c, the introduction of disease into the new world
d. the introduction of the cow and donkey to the new world

Diseases were a huge negative impact. Diseases such as small pox and syphyllis were brought to the Americas by the Europeans and wiped out a large amount of the New World's population. So C is the correct answer

the lowest among the social higher rank were the working class. this class remained detached to the political progression   of the country and was hostile to the other two classes

it granted civil rights to african americans.