Bollywood actor Shah Rukh Khan has responded to the challenge thrown at him by Hrithik Roshan. On September 19, Hrithik had posted a tweet saying, "The 10pack #bangbangdare @iamsrk show us a pic doing ur fav ab exercise!all want 2 know which 1 it is! U hv 3 days! Qabool?" Now, Shah Rukh Khan has posted a video in which he is undergoing a rigorous bodybuilding session. One can figure out his 8-pack abs at the end of the video. He has developed his new physique for his forthcoming film Happy New Year.