Answer:
Inference
Step-by-step explanation:
I mean, it's not difficult.
A theory is an unproven explanation.
An inference is a guess/educated guess where you don't have all the facts.
For example, if "Bob" is caught in the kitchen with a ketchup stain on his shirt, you are inferencing that he used the ketchup.
However, if you see a ketchup bottle nearby or saw it earlier, then it is not, because you already have the facts that ketchup was used.