Which symptoms are indicative of COPD in a 56-year-old male?

The indication of progressive dyspnea is a hallmark symptom of Chronic Obstructive Pulmonary Disease (COPD). Patients with COPD typically experience worsening shortness of breath over time, particularly with exertion. This symptom reflects the gradual deterioration of lung function that characterizes the disease, leading to an increased work of breathing and a reduced capacity for physical activity. The other symptoms listed, while they may present in different contexts, are not specific to the chronic, progressive nature of COPD. For example, acute cough and productive sputum can also occur in short-term respiratory infections rather than being indicative of a chronic condition like COPD. Moreover, a FEV1/FVC ratio greater than 0.70 suggests preserved lung function rather than the obstructive pattern that would be evident in COPD, where this ratio typically falls below that threshold. Thus, the presence of progressive dyspnea is the most appropriate and indicative symptom of COPD in the scenario presented.