What should you exercise when seeing an alternating red and green light gun signal?

When you observe an alternating red and green light gun signal, it is critical to exercise extreme caution. This signal is utilized to convey important information, typically indicating that there is potential danger in the area, such as the presence of other aircraft or obstacles.

Exercising extreme caution means you should be prepared to take appropriate actions to ensure safety while still maintaining control of the aircraft. This heightened state of alertness allows for increased situational awareness, enabling the pilot to make informed decisions in an environment where unexpected issues could arise.

In contrast, the meanings of the other signals are not applicable in this scenario. Proceeding with caution does not convey the level of alertness required when seeing alternating red and green; you need to be more proactive about safety. Executing a go-around or landing immediately implies a more specific course of action that may not be warranted if the signal calls simply for heightened awareness rather than immediate maneuvering or action.