Explanation:

- Option 1: Dia Mirza

- An Indian actress and model known for her work in Bollywood.

- A vocal environmental activist.

- Option 2: Sonam Kapoor

- An acclaimed Indian actress recognized for her style and performances.

- Known for her vegan lifestyle and animal rights advocacy.

- Correct Answer: She was named PETA India's Person of the Year for 2018.

- Option 3: Yukta Mookhey

- A former Miss World and actress.

- Involved in various social causes, but not specifically awarded by PETA in 2018.

- Option 4: Sushmita Sen

- Former Miss Universe and Bollywood actress.

- Engaged in various philanthropic activities, though not PETA's honoree in 2018.