What type of mission would you use when engaging a planned target or target of opportunity that has taken friendly forces under fire?

The correct choice involves utilizing Immediate Suppression or Immediate Smoke when engaging a planned target or target of opportunity that has taken friendly forces under fire. This type of mission focuses on rapidly neutralizing or disrupting the enemy forces that are actively engaging friendly troops, thereby creating a safety buffer. Immediate Suppression is critical in situations where friendly forces are under direct threat, as it prioritizes swift action to alleviate that threat and protect the troops on the ground. The use of immediate smoke can also help obscure the enemy's line of sight or hamper their ability to engage friendly forces effectively.

In contrast, adjust fire missions are typically employed for refining targeting on static or known enemy positions, where a series of corrections may be necessary to effectively engage the target. Suppression missions often involve sustained engagement against enemy positions but may not provide the rapid response needed in immediate contact situations. Finally, FFE (Fire For Effect) is a command that signifies the transition to a more sustained barrage once the target has been adjusted and confirmed, rather than a response to an immediate assault on friendly forces. Therefore, Immediate Suppression or Immediate Smoke appropriately addresses the urgency of the situation.