You can find other articles to see if they have the same information. Do your research on the topic at hand, in other words.
The correct answer is B. Those dogs are Labrador Retrievers.
A predicate noun refers to a noun or a phrase that provide more information about the subject of the sentence. In this case, the 'dogs' are 'Labrador Retrievers.' Since this sentence provided an information about the subject, it is a predicate noun.
The answer is B: doubting
Answer:
The Prince was so angry because the families keep on fighting and distributing the peace of the city. He threatens to kill any one of the Capulets or Montagues that fight again and disturbs the city's peace.