Which alternative source is best suited for site surveys or simul-ations if no floor plans...

When floor plans are not available for site surveys or simulations, the best alternative source to use is the fire escape plan (Option D). Fire escape plans are typically available in most buildings and provide a simplified layout of the premises, including walls, doors, and sometimes the location of permanent fixtures. While not as detailed as architectural floor plans, fire escape plans can offer enough information for initial site survey estimations and RF planning. They allow network designers to understand the basic layout and potential RF obstacles or coverage areas, making them a practical tool for preliminary wireless network planning and simulations in the absence of more detailed floor plans.