How might people adapt to life in an area with steep mountains

People might adapt to life in an area with steep mountains in a number of ways both physiologically as well as the way in which they live their lifestyle. Individuals would most likely become more accustomed to the high altitude over time as well as needing to walk or move across high mountainous features. Additionally people would also adapt to this environment by finding ways to transport themselves and goods through the mountains either through roads or passes and either with motorized vehicles or animals such as donkeys. These are just a few ways that humans might adapt to this environment, but there are many others. 

Ibelieve that the answer is (a).