The term 'delimitation' refers to:

drawing the boundaries of the electoral constituencies

The correct answer is option (3) - drawing the boundaries of the electoral constituencies

The Election Commission of India was set up in January 1950. Sukumar Sen became the first Chief Election Commissioner. The country’s first general elections were expected sometime in 1950 itself. But the Election Commission discovered that it was not going to be easy to hold a free and fair election in a country of India’s size. Holding an election required delimitation or drawing the boundaries of the electoral constituencies. It also required preparing the electoral rolls, or the list of all the citizens eligible to vote. Both these tasks took a lot of time.