What is the requirement for drip legs in relation to potential freezing conditions?

The requirement for drip legs to avoid issues in potential freezing conditions centers on ensuring they are not located in areas prone to freezing. A drip leg, which is designed to collect and remove sediment and moisture from gas lines, must be positioned where it is protected from low temperatures that could lead to freezing water or gas line blockages. If a drip leg is situated in a freeze-prone area, the water could freeze, leading to potential blockages or even damage to the gas line, which can create safety hazards.

Proper installation practices dictate that any component, including drip legs, should be kept in a location that minimizes the risk of freezing. The options addressing insulation, height, and the installation of heaters do not directly solve the fundamental risk associated with the drip leg's location concerning freezing. Therefore, ensuring that they are placed outside of freeze-prone areas is paramount to maintaining functionality and safety, making this the correct choice.