Explanation: When radar targets are displayed at a different bearing than their visual bearing, the most immediate suspect is **incorrect antenna position information**. Here's why: * **Underlying Theory:** A radar system determines a target's bearing by knowing the precise direction the antenna is pointing when it transmits a pulse and receives an echo. This directional data is generated by an encoder or resolver connected to the antenna's rotation mechanism and fed to the display processor. If this sensor provides inaccurate or miscalibrated information, the radar display will show targets at an offset or incorrect bearing, even if the range data is accurate. Let's look at why the other options are incorrect: * **A) A bad reed relay in the antenna pedestal:** While a faulty relay could cause various issues, it's less likely to result in a consistent bearing offset. It might cause intermittent operation or a complete failure of a specific function, but "incorrect antenna position information" is a more direct description of the observed symptom. * **B) A sweep length misadjustment:** Sweep length (or range scale) adjustment affects the *distance* at which targets are displayed, not their bearing. A misadjustment here would cause incorrect *range* information, making targets appear too close or too far, but their angular direction would still be correct relative to the antenna's reported position. * **C) One phase of the yoke assembly is open:** The yoke assembly is part of a Cathode Ray Tube (CRT) display. A fault here would severely distort the display itself, perhaps causing a collapsed or highly distorted image, but it wouldn't specifically alter the *bearing data* being received from the radar antenna. It's a display hardware fault, not a radar data acquisition fault.