Answer : 2. "May 1st"
Explanation :

Answer: B) May 1st Explanation: International Workers' Day, also known as Labour Day in some countries, is a celebration of labourers and the working classes that is promoted by the international labour movement, socialists, communists or anarchists.  It occurs every year on May Day which is May 1st. It is the day to pay tribute to the Labourers. Without them nothing will complete.  In India, the first Labour Day, or May Day, was celebrated in 1923 in Chennai.