Hi Alexander,
Here goes the answer to your question:
Combining enormous physical strength with higher intelligence, the Neanderthals
appear as equipped for facing any obstacle the environment could put in their path, but their relatively sudden disappearance during the Paleolithic era indicates that an inability to adapt to some environmental change led to their extinction.
Neanderthals existed in the past. They do not exist anymore. But the way this sentence has been written, it suggests that they still exist. They “appear” as equipped…. This is the flaw in this sentence.
We need a verb that suggests that Neanderthals are extinct. Now let’s see the sentence with the
correct answer choice:
Combining enormous physical strength with higher intelligence, the Neanderthals
appear to have been equipped to face any obstacle the environment could put in their path, but their relatively sudden disappearance during the Paleolithic era indicates that an inability to adapt to some environmental change led to their extinction.
This choice corrects the verb tense error in the original sentence. Verb phrase “appear to have been equipped” correctly suggests that Neanderthals when alive were equipped to face any environmental problem. They were equipped at that time.
If choice B were worded as “appear to be equipped to face…”, it would be
incorrect because again it would convey the same meaning as Choice A.
Hope this helps.

Thanks.
Shraddha
I understand in this question as "have been equipped" comes after 'to' so it is not a verb .
article that even if hypothetically 'have been equipped' was a verb it would be present perfect tense and not present perfect continuous tense. Can someone explain to me why please.
Is it because for present perfect continuous we need have been <Verb in ing form> and as that is not the case so this is present perfect .
If above is true , can you explain how 'been' is correctly used in the above present perfect