A trained chef at a restaurant with animals can handle certain creatures. According to the code, which creatures is he allowed to care for or handle while at the restaurant?

The correct choice is fish in the aquarium. According to food safety regulations and codes, certain animals are permissible in food establishments under specific guidelines. Fish are often regarded differently because they are largely kept in controlled environments, such as aquariums, where the risk of foodborne illness can be managed effectively. Aquatic species like fish do not interact with food in the same way terrestrial animals do, making it acceptable for food service environments.

In contrast, the other options involve animals that can pose a higher risk to food safety and would typically not be permitted in a restaurant setting. For example, birds in cages or reptiles on display may carry diseases or pathogens that could contaminate food. Similarly, mammals like cats and dogs present health risks and can contribute to sanitation issues, which is why they are generally prohibited in areas where food is prepared and served. Thus, the handling of fish aligns with health regulations allowing for minimal risk within food establishments.