निम्नलिखित में से किस तत्व की उपस्थिति मुख्य रूप से पानी में कठोरता (हार्डनेस) का कारण बनती है?

Which of the following events is considered a major turning point that fueled Indian nationalism during British rule due to its brutal nature and widespread condemnation?

Which of the following events is considered the first major peasant uprising against the British in India?