Which of the following actions is advisable regarding personal hygiene before cooking?

Checking under fingernails is essential for maintaining personal hygiene before cooking because food can easily become contaminated by bacteria and debris that may be trapped there. Clean fingernails help to minimize the risk of cross-contamination, ensuring that any food being prepared does not come into contact with harmful pathogens that could lead to foodborne illnesses. Maintaining proper hand and nail hygiene is a crucial step in food safety practices, as it helps to create a clean working environment.

While other options may have some relevance to cooking or personal care, they do not directly address the specific concerns of hygiene in the kitchen. For instance, using a heavy moisturizer can leave a residue on hands that might transfer to food, compromising cleanliness. Wearing gloves continuously is not required for all tasks and could lead to a false sense of security if gloves are not changed frequently. Lastly, wearing rings can also pose hygiene risks, as they can trap food particles and bacteria, making it harder to keep hands clean. Therefore, checking under fingernails stands out as the most advisable action for ensuring personal hygiene before cooking.