In Case 2, a Woman Was Walking Her German Shepherd

In case 2, a woman was walking her German Shepherd dog in the park. The dog bit a child in an unprovoked attack. The dog had never bitten anyone before. The Court of Appeal decides that the woman is liable and that the ratio is that 'the owner of a dog is liable in negligence for any injury caused in a public place regardless of whether the dog had bitten before or whether the owner was aware of this'.
In case 3, an Alsatian dog bit a postman while in its owner's front garden. The dog had never bitten anyone before. The Court of Appeal decides that the owner is liable on the grounds that 'the principle of liability established in case 2 is applicable, even where the dog is on private property and not in a public place, whether or not the dog has bitten someone before and the owner is aware of this.'
Which of the following facts of case 2 have now become immaterial?

A) That the dog was a German Shepherd.
B) That the dog was in the park.
C) That a postman was bitten.
D) That the dog had not bitten before.