Human population reached the milestone of 1 billion in which year?

The correct answer is Option (4) → 1830

Note 1: NTA dropped this question from the official answer key. The question has been slightly modified so that it has a single correct answer. It is kept for the benefit of students, as it gives them an additional practice question.

Note 2: This question is taken from the pre-rationalised NCERT book. The latest edition (2026-27) does not have this part. An extract of the pre-rationalised NCERT book is given below for the benefit of students.