The widely talked about Akshay Kumar starrer PadMan was released yesterday. As a promotional strategy, the lead Akshay Kumar has been throwing a unique challenge called the 'PadMan' challenge to his colleagues in the film fraternity including his co-star Sonam Kapoor. The challenge is to post a photo of oneself holding a sanitary napkin on their social media. Upon being challenged, Sonam promptly posted a photo of herself holding a pad on her Instagram account which she captioned thus: "Thank you sir! I accept your #padmanchallenge! Yes that's a pad in my hand and I don't feel weird. It's natural, Period!" PadMan, produced by Twinkle Khanna, is based on the life of Arunachalam Muruganantham, who is known for inventing low cost sanitary napkins for rural women.