Why did the Ancestral Puebloans abandon Mesa Verde around the year 1300?

A Attacks from other peoples
B Crop failure
C Avalanches

The ‘Great Drought,’ which lasted from 1276 to 1299, caused repeated years of crop failure, driving the Ancestral Puebloans from their cliff dwellings at places like Mesa Verde, where they had lived for more than 700 years.

The correct answer is Crop failure.