Which NATO operations were conducted in response to the 9/11 attacks?

The correct answer highlights NATO operations that were distinctly tied to the response following the 9/11 attacks. Operation Eagle Assist involved NATO air patrols over the United States, where Allied fighter aircraft were deployed to augment U.S. air defenses. This marked the first time in NATO's history that Article 5, which states that an armed attack against one member is considered an attack against all, was activated in direct response to an attack on a member nation.

Operation Active Endeavour was another significant NATO operation initiated as a result of 9/11, involving the deployment of naval forces to the Mediterranean Sea to deter terrorism and enhance security in the region. This operation aimed to ensure maritime security and counteract potential terrorist activities.

These operations exemplified NATO's collective defense principle and demonstrated international cooperation in response to a global security threat. The link to 9/11 is critical as both operations were initiated to protect member states following the attacks, showcasing a unified front against terrorism in the aftermath.

The other options listed refer to operations that, while significant in their own right, do not directly correlate to the immediate NATO response to the 9/11 attacks.