Which term reflects a lack of sophistication in behavior?

The term "uncouth" describes behavior that is lacking in refinement, taste, or sophistication. It is often used to refer to actions or manners that are socially awkward, crude, or unsophisticated. When someone exhibits uncouth behavior, they may disregard social norms or exhibit a lack of polish that is typically expected in polite society. This term effectively captures the idea of a deficit in social grace and cultural understanding.

In contrast, the other options do not convey the same meaning. "Tawdry" refers to something that is showy but of poor quality, often associated with cheapness or a lack of taste, but does not specifically address behavior. "Stupefy" means to shock or astonish someone into a state of confusion or bewilderment, rather than a lack of sophistication. "Ubiquitous" describes something that is present everywhere at once, which does not pertain to behavior or sophistication. Thus, "uncouth" is the most fitting choice to describe a lack of sophistication in behavior.