According to the GOLD guidelines, which of the following definitions of chronic obstructive pulmonary disease is MOST ACCURATE?
a) It is a common, preventable, and treatable disease characterized by reversible airflow limitation.
b) It is an uncommon and treatable disease characterized by reversible airflow limitation.
c) It is an uncommon and treatable disease characterized by irreversible airflow limitation.
d) It is a common, preventable, and treatable disease characterized by irreversible airflow limitation.