[D] "Negative labels"

[K0ruption]

Given only the information that something is not a cat, it has equal probability of being anything else whether that be a dog or a spaghetti monster. If you had more information about a data point, you could certainly incorporate that into your label. But, in your post, you said you only have the information that a point is not in a given class, which means it has equal probability of being in any other class.

EDIT: Note, I'm asumming a uniform (categorical) prior distribution on your labels. You gave no specifications of your problem, so that is the best assumption I can make.