(c) The countries of south America and Africa
The Aztecs and Mayans were two Mesoamerican civilizations that had much in common. Both civilizations observed 365 day calendars with similar markings and day/month symbols. They also both worshipped a pantheon of gods during religious ceremonies, some of which involved human sacrifice.
This would be the north as back during the reconstruction era, the north (Tom Watson's group) wanted to be more efficient and industrialized.
Reference: Georgia Studies Unit 6 notes
Answer:
The 12 survivors are people who are married (6 couples), the word "single" is the keyword denoting those only people who are single had died.