Question

what did the mayas develop?
intricate roads to connect different parts of their empire
stone carvings that showed images of their rulers
a calendar based on a solar year of 365 days
an urban area with a system of canals

Explanation:

The Maya civilization is known for advanced astronomical and calendrical systems. Their solar calendar (Haab') was precisely based on a 365-day year. The other options correspond to other civilizations: intricate roads are linked to the Inca, stone carvings of rulers are not their defining development, and canal-based urban areas are associated with the Aztec (Tenochtitlan).

Answer:

a calendar based on a solar year of 365 days