What triggers a cough related to gastroesophageal reflux disease (GERD)?

Cough related to gastroesophageal reflux disease (GERD) is primarily triggered by acid irritation. In GERD, stomach acids flow back into the esophagus, leading to irritation of the esophageal lining. This acidic contact can stimulate the vagus nerve, which in turn activates a reflex that leads to coughing as a protective mechanism for the airway, attempting to clear the irritant.

The other options, while potentially related to respiratory symptoms, do not accurately capture the primary mechanism by which GERD causes a cough. Excess mucus and post-nasal drip are more commonly associated with upper respiratory conditions rather than GERD itself. The sneeze reflex is also a distinct response to nasal irritation, not a direct result of acid reflux. Thus, the primary driver for cough in the context of GERD is indeed the irritation of the esophagus by the acidic contents from the stomach.