This question asks which actress first lent her face to the Lux soap campaign in India.
Madhubala: She became a top Lux face during the 1950s, but her campaigns came after the brand had already started using film stars in India, so she was not the first.
Leela Naidu: She appeared in Lux ads later, well after the practice was already established, so this is wrong.
Suraiya: She was a popular singer-actress endorsed by Lux in the 1940s, but records point to an earlier face for the brand, so this is wrong too.
Leela Chitnis: Leela Chitnis is credited as the first Indian film actress to endorse Lux soap, starting the long running tradition of Bollywood stars fronting the brand.
So option D, Leela Chitnis, is correct.
Let's summarize:
Leela Chitnis opened the door for decades of Bollywood actresses becoming the face of Lux soap.
This is a niche but recorded piece of Indian advertising history.