Which of the following is the oldest and still most widely used RADAR Countermeasure?

Chaff is the oldest and still most widely used radar countermeasure due to its effective method of creating false targets on radar screens. When deployed, chaff consists of small strips of metalized material that scatter radar signals, effectively confusing enemy radar systems. By representing multiple false returns, chaff can obscure or mask the actual target, making it difficult for radar operators to track or lock onto the intended aircraft or missile.

The widespread use of chaff in various military applications, from aircraft to naval vessels, underscores its importance as a reliable and simple countermeasure against radar-guided systems. Its ability to disrupt radar tracking with minimal complexity has ensured its ongoing relevance in electronic warfare, despite the development of more advanced countermeasures.

Other options, while also effective in their own right, do not have the same historical legacy or broad applicability as chaff in the context of radar countermeasures. Flares, for instance, are primarily designed to counter infrared guidance systems rather than radar. Towed decoys and TALD offer sophisticated solutions for specific scenarios but are not as universally used or as longstanding as chaff.