What safety measure must be taken concerning open flame cooking devices on balconies?

Open flame cooking devices, such as grills, pose significant safety hazards, especially in residential settings like balconies. The correct answer highlights that these devices cannot be installed on balconies due to the increased risk of fire that they present in such environments.

Balconies are often part of multi-family dwellings where the proximity of units can lead to a fire spreading quickly if an open flame device is improperly used or maintained. Restrictions on their installation are generally in place to protect the safety of all residents.

Safety regulations typically require that open flame cooking devices be used in designated areas specifically equipped to handle potential fire risks, such as designated outdoor grilling areas away from buildings. This is to help ensure that the risk of fire is minimized and that appropriate fire safety measures can be effectively implemented.

The other options suggest possibilities that do not align with the inherent risks associated with using open flames in close quarters, overlooking the imperative need for stringent safety measures in high-density living situations.