Railway Minister Ashwini Vaishnaw reviewed the trial of the Automatic Train Protection System, 'Kavach', and oversaw the upgrades made to the system. In how many different emergency situations did the Kavach system function as expected during the trial?

### Concept & Verification Current affairs related to Indian Railways' technological advancements, specifically the indigenous Automatic Train Protection System (Kavach). ### Step-by-Step Solution * Railway Minister Ashwini Vaishnaw inspected the Kavach 4.0 system trials. * During the extensive trial runs, the system was tested to ensure train safety under critical conditions. * The Kavach system was evaluated and functioned successfully across 3 distinct emergency situations, such as passing a signal at danger and preventing head-on collisions. ### Exam Strategy & Shortcut Memorize key metrics of major national infrastructure projects. Kavach trials typically test the core 3 collision/emergency scenarios. ### Common Pitfall Guessing a higher number like 7 or 10 assuming "more tests means better safety," without knowing the exact parameters of the public trial. ### Final Answer Therefore, the correct answer is **3**.