The correct answer is 3) a stone calendar.
The Aztecs adopted the following aspect of Maya civilization: a stone calendar.
The Mayas of the Yucatan peninsula of Mexico were great astronomers that developed three kinds of calendars. The Haab is a 365-day solar calendar. It is divided into 18 months with 20 days. It has an outer ring depicting the months using glyphs. Another calendar was the Tzolkin, a divine calendar of 260 days divided into 20 periods of 13 days. It was used to establish religious ceremonies. The other calendar was the Long Count, an astronomical calendar used for longer periods.
The Aztecs adopted the Haab calendar. The original Aztec Calendar rock can be admired in the great Museum of Anthropology in Mexico City.
