Explain your reasoning for the item you ranked as the #1 most impactful change. European colonization’s
1 Disease

So, if I am understanding your question, we are talking about the black plague. There are many reasons why this plague was an impactful change, some being that it helped humans understand the importance of hygiene (during those time, hygiene was very poor) as well as the importance of social distancing and overall the understanding of viruses. It helped society improve from their mistakes and become a much safer and modern society than it was before.

the answer to your question is ( syngman rhee) have a great day