A sensor network monitors the temperature and humidity of buildings. A company may own one or more buildings; however, the entire sensor network does not belong to any of the companies. Each sensor has a probe type (temperature or humidity) and a MAC address which is considered globally unique. A sensor is always located inside a building. A building may contain multiple sensors. When a sensor reading is performed, the data along with a timestamp is stored in a database.

You are required to draw an entity relationship diagram (ERD) representing the above scenario. Be sure to list any assumptions you make and show all attributes for each entity.