Final answer:
The Aztec adaptation to their environment that represents irrigation systems is their development of chinampas. These were raised planting-beds on floating platforms, which allowed for efficient agricultural practices.
Step-by-step explanation:
The adaptation of the Aztecs to their environment that is being referred to in this question is c) Irrigation systems. The Aztecs developed an intricate system of chinampas, which were raised planting-beds on floating platforms in Lake Texcoco. This form of agriculture allowed them to control soil fertility and watering very carefully. Moreover, they even constructed a to separate fresh water from brackish water and brought fresh water into Tenochtitlan via an aqueduct. This system of chinampas was extremely efficient, supporting a dense population by enabling intensive agriculture in an urban environment.