What is the appropriate action if vomiting occurs in a passenger?

Providing an airsick bag is the most appropriate action if a passenger begins to vomit. This action ensures that the passenger has a proper means to manage their symptoms and maintain hygiene during a distressing situation. Airsick bags are designed for this purpose and can help prevent mess and discomfort, facilitating a more manageable experience for the affected individual.

Offering food immediately is not advisable as it could exacerbate the situation, potentially leading to more vomiting. Ignoring the symptoms is also not an appropriate approach, as it does not address the immediate need of the passenger. Additionally, restricting liquid intake without assessing the situation could lead to dehydration or further complications, especially if the passenger is feeling unwell. The focus should be on providing the passenger with a means to cope with their vomiting effectively.