How would you describe the Columbian Exchange as an environmental transformation?

a.
Crops coming from Europe for cash crops like sugar and grapes while new world plants go to Europe-tomatoes to Italy, potatoes to Ireland- and increased caloric food increases the diet.

b.
Animals are transferred as well, where some animals, like pigs, could become pests.

c.
Biggest effect would be transfer of Old World diseases (90% died of diseases).

d.
A and B

e.
B and C

f.
All of the above

g.
None of the above