Which building must be prepared for live fire evolutions?

Preparing all buildings used in the scenario for live fire evolutions is crucial for several reasons. Ensuring that every structure is adequately prepared allows for a comprehensive understanding of fire behavior, smoke movement, and the effectiveness of various firefighting tactics in diverse environments. When training scenarios incorporate different types of buildings, it better reflects real-life situations that firefighters may encounter, fostering adaptability and improving operational readiness.

Additionally, preparing all structures ensures that safety protocols are consistently applied throughout the training environment, allowing for thorough risk assessments and effective emergency response planning. This holistic approach to training promotes a deeper grasp of how fires can interact with different building materials and designs, ultimately enhancing the skills and knowledge of the trainees.

The other options suggest limiting the preparation to either specific buildings or types of structures, which would hinder the educational experience and risk overlooking critical lessons that can be learned from engaging with various building designs in a live fire context.