What device alerts the remote pilot to indicate dangerous or irregular flight conditions?

The device that alerts the remote pilot to indicate dangerous or irregular flight conditions is the warning lights and annunciator alarms. These systems are designed to provide immediate and clear alerts to the pilot in scenarios where there may be an issue with the drone's operation. For example, if the drone's battery charge is low or if there are issues with the propulsion system, the warning lights or alarms serve as a crucial signal that necessitates immediate attention and potential corrective action.

In contrast, the other options do not provide timely alerts in the same manner. A GPS system primarily offers location and navigational data, which is essential for flight management but does not inherently alert pilots to irregular conditions. The remote control transmitter is used for piloting the aircraft but does not alert the pilot to flight conditions. Telemetry data links are responsible for transmitting data about the aircraft's performance and position, but they primarily serve to relay information rather than signal immediate alarms about dangerous conditions.