The earliest Mayan pottery found at Colha, in Belize, is about 3,000 years old. Recently, however, 4,500-year-old stone agricultural implements were unearthed at Colha. These implements resemble Mayan stone implements of a much later period, also found at Colha. Moreover, the implements' designs are strikingly different from the designs of stone implements produced by other cultures known to have inhabited the area in prehistoric times. Therefore, there were surely Mayan settlements in Colha 4,500 years ago.

Which of the following, if true, most seriously weakens the argument?

• ACeramic ware is not known to have been used by the Mayan people to make agricultural implements.  
• BCarbon-dating of corn pollen in Colha indicates that agriculture began there around 4,500 years ago.  
• CArchaeological evidence indicates that some of the oldest stone implements found at Colha were used to cut away vegetation after controlled burning of trees to open areas of swampland for cultivation.  
• DSuccessor cultures at a given site often adopt the style of agricultural implements used by earlier inhabitants of the same site.  
• EMany religious and social institutions of the Mayan people who inhabited Colha 3,000 years ago relied on a highly developed system of agricultural symbols.