What is the primary indication for using a combination inhaler?

A combination inhaler typically contains two different types of medications that work together to effectively treat and manage asthma symptoms. The primary indication for using such an inhaler is to provide both quick relief and long-term control of asthma, which can help in reducing both the frequency and severity of asthma attacks.

Combination inhalers often include a corticosteroid to reduce inflammation and a long-acting beta-agonist (LABA) to help open the airways, improving airflow and decreasing breathlessness. This synergistic effect ensures that individuals with asthma experience better overall management of their condition, making C the most suitable choice in this context.

In contrast, options like treating infections or managing allergy symptoms do not align with the primary function of combination inhalers. Moreover, providing hydration is unrelated to the purpose of inhalers, further clarifying why they are not correct choices.