Answer:
A
Explanation:
A talks about one war being more horrific than the other, which is up to opinion. For example, I may think World War 1 was more horrific, but you may think World War 2 was more horrific. It is an opinion.
A majority of the world's countries participating in World War 2 is a fact. 30 nations participated in World War 2, which is a fact and is not up to opinion.
Japan's surrender ending the War is a fact, the war did end when Japan surrendered, it is not an opinion.
The amount of deaths that happened in the war is a statistic, which is purely factual.