Which term best describes the proactive use of mine countermeasures?

The term that best describes the proactive use of mine countermeasures is offensive (proactive). This approach emphasizes taking initiative to neutralize potential threats before they can cause harm. In the context of mine countermeasures, this can involve actively seeking out and clearing mines in areas where operations may take place, thus ensuring safer navigation and the protection of assets.

By adopting offensive measures, naval forces can prevent future encounters with mines and mitigate risks early on, leading to increased operational effectiveness. This proactive stance is crucial in maritime operations where mine threats could otherwise impede mission success and endanger naval personnel and equipment. Other options suggest either passive or reactive responses, which do not align with the essence of a proactive strategy aimed at neutralizing threats ahead of time.