Which of the following is considered a component of Passive Air Defense?

Passive air defense encompasses measures that are intended to protect assets and personnel without direct confrontation with the enemy, primarily focusing on reducing vulnerability to enemy attacks through various means. One of the key strategies in passive air defense is evading detection through concealment, which includes tactics such as camouflaging military installations, using terrain to obscure visibility, and employing deception methods to mislead potential adversaries.

By focusing on the passive measures, military forces can increase their survivability and reduce the likelihood of successful enemy targeting without relying on active engagement, which involves direct confrontation or interception of threats. Concealment is particularly critical in warfare as it helps to mitigate risks and can significantly impact the effectiveness of an enemy's offensive operations.

In contrast, the other options involve active measures that either engage or intercept enemy threats directly, such as missile interception, ground-to-air combat operations, and engaging enemy aircraft directly, which fall under active air defense. Therefore, the choice of evading detection through concealment accurately aligns with the principles of passive air defense.