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.
Answer:
66. I took off my shoes in order not to make noise.
67. I've found the book which I was looking for in the morning.
68. It was a shame that Lauren couldn't come to the party.
69. The road was so icy that they couldn't drive.
70. I went to school as usual yesterday although I had a terrible cold.
71. The children ran away after they broke the window.
72. His brother is now working in Liverpool which is a big city of England.
Answer: C.
Explanation: If you sing it out you will hear yourself saying ABCB.