How often must exacerbations occur in mild persistent asthma?

In the context of mild persistent asthma, exacerbations are defined as episodes where asthma symptoms worsen and may require increased treatment intervention. For a diagnosis of mild persistent asthma, it is specified that the individual experiences at least two exacerbations within a year that require the use of systemic corticosteroids, such as oral corticosteroids. This criterion helps to categorize asthma severity based on the frequency and intensity of exacerbations.

Option B accurately reflects this standard by stating that 2 or more exacerbations requiring oral corticosteroids occurred over the last year. This aligns with the clinical definitions and guidelines utilized for classifying asthma, ensuring that the assessment of asthma control incorporates both the frequency of symptoms and the need for escalated therapy.

Other choices propose different frequencies or intensities of exacerbations, but only the specified two or more within the year accurately captures the scope of mild persistent asthma, which is characterized by symptoms that occur most days but are not persistent and do not significantly disrupt daily activities.