Which of the following is a symptom commonly associated with COPD?

Clubbing in the upper digits is often associated with chronic respiratory conditions, including Chronic Obstructive Pulmonary Disease (COPD). This finger clubbing occurs as a response to long-term oxygen deprivation in the body, which is common in COPD due to chronic bronchitis and emphysema. The chronic inflammation and damage to lung tissue can lead to a decrease in oxygen levels, causing changes in the nails and fingertips.

In contrast, the other options do not accurately represent symptoms associated with COPD. Increased lung volume is typically not observed in COPD; instead, there is usually a decrease in lung function over time. Decreased respiratory rate is also not typical, as patients often experience an increased respiratory rate due to difficulty breathing. Improved exercise tolerance would contradict the effects of COPD, which generally results in decreased capacity for physical activity.