Which of the following is required for safety in Class B airspace?

In Class B airspace, which encompasses the area around busy airports, safety requirements are enhanced due to the high volume of air traffic. One of the critical safety measures is that all aircraft operating within this airspace must be equipped with a transponder that has altitude reporting capability. This enables air traffic control (ATC) to accurately track aircraft altitude and position, which is vital for maintaining safe separation between multiple aircraft operating in close proximity.

The transponder's altitude reporting function allows ATC to provide precise instructions and traffic advisories, thereby reducing the risk of mid-air collisions. This is particularly important in Class B airspace where the density of air traffic is higher than in other classifications, requiring more stringent safety protocols. Therefore, having a transponder with altitude reporting not only ensures compliance with regulations but also significantly enhances operational safety.

Other options, such as using a basic transponder without altitude reporting, only adhering to visual flight rules, or considering communication with ATC as optional, do not meet the necessary safety standards required for operating in Class B airspace. These alternatives do not provide the same level of situational awareness and tracking accuracy needed in a busy and sometimes congested airborne environment.