Aztec chinampas and Inca terraces are examples of

A the influence of Spanish culture.

B adaptations to physical geography.

C reactions to oppressive governments.

D the continuation of Olmec traditions.

Aztec chinampas and Inca terraces are examples of adaptations to physical geography (B).

The Aztecs created chinampas on shallow lakes by tangling reeds with stakes until soil and vegetation would accumulate underwater and be high enough to immerge over the surface. These patches of land were very fertile and used to grow crops.

The Incas' agricultural terraces are believed to have served the purpose of "teaching" crops they brought back from other lands to grow at different altitudes. The land was levelled in gradual height steps, so they would plant the crop at the center, which was the warmest, and then progressively move it upwards until it had adapted to their climate.

As you can see, these are two examples of civilizations adapting their agricultural practices to the geography of the land they lived in.