Final answer:
The characteristic least associated with emphysema is a productive cough throughout the day option (C); other common features are a barrel chest appearance, cor pulmonale, and polycythemia.
Step-by-step explanation:
The characteristic least associated with emphysema is Productive cough throughout the day option (C). Emphysema, part of chronic obstructive pulmonary disease (COPD), primarily involves the breakdown of lung tissue, specifically the alveoli, leading to impaired gas exchange, shortness of breath, and reduced airflow. Symptoms specific to emphysema include a barrel chest appearance due to air becoming trapped in the lungs, cor pulmonale which signifies right-sided heart failure resulting from lung pathology, and polycythemia, an increased number of red blood cells due to chronic low oxygen levels. A productive cough throughout the day is more indicative of chronic bronchitis, another form of COPD. Spirometry is an important diagnostic tool that measures airflow to help confirm cases of COPD.