What is a response used by a gun team when they are under fire?

In a situation where a gun team is under fire, "Return Fire" is the appropriate response. This action is essential as it serves to engage the enemy who is actively attacking the team, providing both self-defense and the opportunity to suppress enemy fire. Engaging the threat can also protect the team and potentially allow for maneuvering or withdrawing if necessary.

Returning fire is a fundamental tactic in combat situations, as it allows for the maintenance of fire superiority, which is critical for the survival and effectiveness of the unit. It also acts as a deterrent, signaling to the enemy that they are being engaged and that their actions can have immediate consequences.

Other options such as "Observation," "Check," and "Cease Fire" do not align with a direct response to being under fire. Observation may be part of situational awareness and monitoring enemy movements, but it does not actively address the immediate threat. Checking involves verifying information or conditions, which can be useful in different contexts, but does not directly respond to enemy fire. Cease Fire is a command used to stop all firing, which is contrary to the need for self-defense and counteraction against an aggressor.