What happens when both the Pitot tube and the static port are blocked with ice?

When both the Pitot tube and static port are blocked with ice, all the readings become frozen and unusable, which leads to the situation described in the correct answer. The Pitot tube measures dynamic pressure, which is essential for the airspeed indicator to function, while the static port measures ambient atmospheric pressure, which is crucial for the altimeter and vertical speed indicator.

If ice blocks the Pitot tube, the airspeed indicator will not receive the dynamic pressure information it needs to display correct airspeed. Similarly, if ice blocks the static port, the altimeter and vertical speed indicator will not function properly as they rely on accurate static pressure measurements. With both components obstructed, the instruments will essentially "freeze" at their last indicated values, making them unreliable for the pilot.

This situation can lead to dangerous flight conditions, as the pilot may not have accurate information about speed, altitude, or vertical rate of climb/descent, impacting decision-making and safety.