<|system|>
Select the vertebrate.
A: polar bear
B: redback spider</s>.
<|user|>
Can you answer based on context?
<|assistant|>
A polar bear is a mammal. Like other mammals, a polar bear is a vertebrate. It has a backbone.
Like other spiders, a redback spider is an invertebrate. It does not have a backbone. It has a hard outer cover.