One way farmers living in arid climate zones have adapted to the environment include

Farming drought-resistant crops

Explanation:

There were no options but this is one of the main ways that farmers in arid areas have adapted to the climate there.

Arid areas are areas with little to no water such as deserts and this has imparted their ability to retain vegetation negatively leading to a sparse flora presence.  

For people living in such areas, growing enough food to eat can be challenging due to the lack of water. To combat this famers have instead planted drought resistant crops such as sorghum, cassava and groundnuts. Advancements in biotech over the last two to three decades have also led to more resistance in other crop varieties such as maize (Drought Tolerant Maize).

answer; the correct answer is chemical: