In the context of conventional buildings, what defines the zone of protection?

The zone of protection in conventional buildings is fundamentally defined as the space beneath a protective system that is designed to safeguard structures from lightning strikes. The choice describing the space under a 150-foot radius sphere that is tangent to any two air terminals captures this concept accurately.

This sphere represents the theoretical area within which a lightning strike may occur safely and be diverted to the ground through the air terminals and their connected grounding systems. Air terminals, also known as lightning rods, are installed to provide a preferred point for a lightning discharge to strike, thereby facilitating the safe transmission of the lightning's energy away from the building and its occupants.

By ensuring that the space beneath this theoretical sphere is well-protected, building owners can minimize the risk of direct lightning strikes and the potential damage they cause. This approach not only considers the vertical height of the building but also extends outwards horizontally, thus defining the complete zone of protection.

Other options do not encompass the correct scope of the zone of protection as defined in established standards and best practices for lightning protection systems.