Which display provides all primary attitude and flight information to the pilots?

The Primary Flight Display is the correct choice because it is specifically designed to present all essential flight information to the pilots in a clear and organized manner. This display integrates critical data such as altitude, airspeed, heading, vertical speed, and attitude, effectively consolidating the information needed for flight operations into a single visual interface.

By offering a primary view of the aircraft's orientation and essential flight parameters, the Primary Flight Display enhances situational awareness and aids the crew in monitoring and controlling the aircraft during flight phases. This is especially important in a multi-function display environment, where it may be easy to become overwhelmed with information or lose sight of critical flight variables.

The other options do not encompass the complete range of primary information that pilots rely on for safe flight operations. For example, the Multi-Function Display provides various data and can be programmed for different functions but does not serve as the sole source of primary flight data. Meanwhile, the Vertical Speed Indicator and the Attitude Indicator are components of the flight information system but do not provide a comprehensive view on their own.