Sentence Correction

Please provide me explanation with these question

1. Combining enormous physical strength with higher intelligence, the Neanderthanls appear as equipped to face any obstacle the environment could put in their paths, but their relatively sudden disappearance during the paleolithic era indicates that an inability to adapt to some environment led to their extinction.

a) appear to have been equipped to face any obstacle the environment could put in their paths
b) appear as equipped for faceing any obstacle the environment could put in their paths

2. A 1972 agreement between Canada and the united states reduced the amount of phosphates that municipalities had been allowed to dump into the Great Lakes

a) reduced the amount of phosphates that municipalities are allowed to dump

In Question 1, i am confused why "to have been" is used. What is the meaning difference between original choice and option a

Similarly in question 2, what is the meaning of both the option. Why "had been" is wrong. How nd when to used "had been"

Thanks

Have and has been are the past perfect form of to be. This is used when you are talking about events over a period of time (as in number 1) or to show the order of multiple events in a row (number 2 - though number 2 also falls in the category for the first reason)