How did geography affect the construction of the Inca Road system?

The construction of roads varied based on the climate, elevation, and materials available to the Inca.
The construction of roads is largely unknown because many of the roads and bridges have disintegrated over time.
The construction of roads was similar throughout the empire, always using large paving stones to prevent erosion.
The construction of roads was only done at the lowest elevations because of available materials and ease of movement.

The correct answer is:

The construction of roads varied based on the climate, elevation, and materials available to the Inca.