Answer: (1) National Legal Services Authority vs. Union of India
Explanation:
The Supreme Court of India in the landmark case of National Legal Services Authority (NALSA) vs. Union of India (2014) recognized transgender persons as the 'third gender.' This judgement was historic as it affirmed the rights of transgender individuals under the Indian Constitution. The court ordered that job applications and other official documents should include a separate column for the third gender. This judgement was a significant step towards ensuring equality and non-discrimination for transgender people in India.
The other cases listed, such as Suresh Kumar Koushal vs. Naz Foundation (which dealt with the decriminalization of Section 377), Navtej Singh Johar & Ors vs. Union of India (which also pertained to Section 377 and LGBTQ rights), and Justice K. S. Puttaswamy (Retd.) & Anr. vs. Union of India (which was about the right to privacy), do not directly address the recognition of transgender persons as the third gender. Therefore, the correct answer is National Legal Services Authority vs. Union of India.