Pyramid-building civilizations in South America date back as far as 15

Pyramid-building civilizations in South America date back as far as 1500BC. Based on the similarities between these ancient cultures and the roughly contemporary pyramid-building cultures of Egypt, some archeologists believe that the South American societies were founded by Egyptians who traveled to South America on reed boats.

Which of the following, if true, would most seriously weaken the hypothesis given above?

A. Most South American pyramids are religious structures, while most Egyptian pyramids are tombs.
B. Egyptian borrowed the idea of reed boats from the Phoenicians, who invented them in 900BC .
C. South Americans today often use reed boats.
D. Modern attempts to duplicate the hypothesized voyage across the Atlantic in a reed boat have been unsuccessful.
E. South American pyramids and Egyptian pyramids are not built from the types of stone.