What procedure should be followed if the "Low Fuel" caution indicator is activated?

When the "Low Fuel" caution indicator is activated, the appropriate action is to execute the "Fuel" BOLDFACE procedures. This is vital because it ensures that the pilot responds promptly and correctly to a potentially critical situation regarding fuel levels.

The "Fuel" BOLDFACE procedures are specifically designed to address low fuel conditions and outline the necessary steps to manage fuel effectively, thereby enhancing the safety of the flight. These procedures are critical as they provide systematic guidance that may include actions to take for conserving fuel, checking fuel quantities, and preparing for an emergency landing if fuel becomes critically low.

While the other options may seem relevant, they either do not provide immediate and proactive management of the fuel situation or fall outside the established procedures for handling the low fuel caution. Engaging the reserve fuel tanks might not be an option if those systems are not active or applicable to the situation, and contacting air traffic control, while useful for general communication, does not directly address the urgent need to manage low fuel conditions effectively. Thus, executing the "Fuel" BOLDFACE procedures remains the most direct, safety-oriented, and protocol-driven response to the activation of the low fuel caution indicator.