Final answer:
Geographical variations directly influence cultural practices, as detailed by the study of cultural ecology, which examines the interactions between cultural practices and the physical environment.
Step-by-step explanation:
In reaching her destination, a backpacker encounters diverse landscapes and climates, which can influence a variety of social factors due to the geographical variations in the area. Among the options given, the most direct influence of these geographical varieties is on cultural practices. This concept, known as cultural ecology, is a part of geographical studies that examines the interactions between cultural practices and the physical environment. Environments dictate many aspects of life, including what crops can be grown, which in turn influences the food available and the dietary habits of a society. Furthermore, certain geographical features can lead to specific sports, traditions, or even architectural styles that become a part of the cultural identity of a place.