What are the components of the standby instruments?

The standby instruments in an aircraft are designed to provide critical flight information in the event of primary instrument failure. Option B correctly identifies the key components of these standby instruments, which typically include an airspeed indicator, altimeter, attitude indicator, turn/bank indicator, and a magnetic compass.

The inclusion of the attitude indicator is particularly important, as it provides essential information about the aircraft's orientation relative to the horizon, an aspect of flight that must be monitored continuously for safe operation. The airspeed indicator and altimeter help pilots maintain awareness of the aircraft's speed and altitude, which are vital for control, especially in various phases of flight like takeoff, landing, and during turbulence. The turn/bank indicator assists pilots in managing their rate of turn and ensuring standard rate turns, while the magnetic compass serves as a backup navigation reference, particularly valuable in instrument meteorological conditions when visibility may be poor.

The other options contain partial or incorrect combinations of instruments that do not fully represent the comprehensive set that standby systems offer, which can jeopardize situational awareness if relied upon in flight.