Which of the following symptoms can indicate asthma?

Variable symptoms with airflow obstruction is the correct indication of asthma. Asthma is characterized by a range of symptoms including wheezing, shortness of breath, chest tightness, and coughing, which can vary in intensity and frequency. The presence of airflow obstruction is a fundamental feature of asthma, as it reflects the narrowing of the airways that occurs during an asthma attack or exacerbation. This variability is key in distinguishing asthma from other respiratory conditions which may present with more consistent symptoms.

Persistent cough, while it can be a symptom of asthma, is not adequate on its own to signify the condition without the accompanying variable airflow obstruction. Increased appetite and weight gain are not typical symptoms associated with asthma and do not provide any indication of the disease's presence. Addressing asthma involves recognizing not just the occurrence of cough but the pattern and variability of symptoms related to airflow limitations.