Which symptom is most associated with allergic rhinitis?

Allergic rhinitis, commonly known as hay fever, is primarily characterized by the body's immune response to allergens, such as pollen, dust mites, or pet dander. The symptoms that are most prevalent in this condition typically involve the eyes and nasal passages. Watery eyes are a hallmark symptom of allergic rhinitis due to the overproduction of tears in response to allergens. This reaction occurs because allergens trigger the release of histamines, leading to inflammation and irritation of the conjunctiva and mucous membranes.

In this context, the presence of watery eyes aligns perfectly with the typical symptom profile of allergic rhinitis, making it the most associated symptom among the options provided. The other symptoms listed, such as fever, halitosis, and persistent cough, are not typically linked with allergic rhinitis. Fever is more indicative of infectious processes, halitosis often relates to oral hygiene issues, and while a cough can occur in conjunction with upper respiratory symptoms, it is not a defining feature of allergic rhinitis. Thus, watery eyes stand out as the most characteristic symptom of this condition.