Test Facts vs opinions: the key to constructive debate

QUESTION 1: What is the fundamental difference between a fact and an opinion?

There is no difference, both are valid in a debate
A fact is a personal belief and an opinion is a universal truth
Fact is a verifiable and objective statement, while an opinion is subjective and cannot be proven
A fact is always scientific and an opinion is always emotional

You have no idea what you're talking about
I understand your point of view, but I see it differently and these are my reasons
That's the dumbest opinion I've ever heard
I'm not going to argue that with you