The correct answer is C.
Ancestral pueblo were a native American culture. They lived in the so-called Four Corners region, that comprises territories in Utah, Arizona, New Mexico and Colorado.
Along the 12-13th century they migrated south, leaving their established homesand communities. They reason is still unclear, but researchs appoint to long lasting droughts, soil erosion, and other severe weather conditions.
see if this helps ^-^