Opinions are ideas that are completely subjective (based on how other people feel, not by proven facts) and cannot be proven to be true or false.
The other options can be concretely proven and are thus facts. This is especially true for numerical values. For example, if stated A > B, then it is a fact that A is greater than B.
The question of which cat has the most attractive coat can vary from person to person. I may say that one specific cat has the most attractive coat, while you may disagree and say that another one has a more attractive coat.
