Which term best describes someone who feels discomfort in urban life?

The term "rustic" is the most fitting choice to describe someone who feels discomfort in urban life because it generally refers to a person who prefers rural or countryside settings over urban environments. Rustic connotes a connection to the simplicity, tranquility, and natural aspects of rural living, which contrasts with the hustle and complexity of city life. Someone who is described as rustic may find urban settings overwhelming or unappealing, leading to feelings of discomfort.

The other choices do not align as closely with the context of discomfort in urban life. "Itinerant" refers to someone who travels from place to place, often for work, and does not specifically denote discomfort in cities. "Fickle" describes someone prone to sudden changes in behavior or opinions, which does not relate to urban discomfort. "Coy" refers to being shy or pretending to be shy, often in a flirtatious manner, and does not apply to the concept of urban discomfort. Thus, "rustic" aptly captures the intended meaning.