GMAT Reading Comprehension (RC) | Re: Anthropologists studying the Hopi people of the

Can anyone explain the second question?

My interpretation:

".. attributed to the Hopi religiouselite’s determined efforts to preserve their religion and way of life, and also to ageographical isolation greater than that of many other Native American groups, an isolation that limited both cultural contact and exposure to European diseases.But equally important to Hopi cultural persistence may have been an inherent flexibility in their social system"

There are two factors - preserve