Task: Question Answering
Input (English): The pregnant Bride and her groom rehearse their wedding. Bill, the Bride's former lover, the father of her child, and the leader of the Deadly Viper Assassination Squad, arrives unexpectedly and orders the Deadly Vipers to kill everyone at the wedding. The Bride survives and swears revenge.Four years later, the Bride has already assassinated Deadly Vipers Vernita Green and O-Ren Ishii. She goes to the trailer of Bill's brother and Deadly Viper Budd, planning to ambush him. Budd has been warned by Bill of her approach; he shoots her in the chest with a shotgun blast of rock salt, then sedates her. He calls Elle Driver, another former Deadly Viper, and arranges to sell her the Bride's unique sword for a million dollars. He seals the Bride inside a coffin and buries her alive.Years earlier, Bill tells the young Bride of the legendary martial arts master Pai Mei and his Five Point Palm Exploding Heart Technique, a death blow that Mei refuses to teach his students; the technique will supposedly kill any opponent after he or she takes five steps. Bill takes the Bride to Mei's temple for training. Mei ridicules her and makes her training a torment, but she gains his respect. In the present, the Bride uses Mei's martial arts techniques to break out of the coffin and claw her way to the surface.Elle arrives at Budd's trailer and kills him with a black mamba hidden with the money for the sword. She calls Bill and tells him that the Bride has killed Budd, and that Elle has killed the Bride. She uses the Bride's real name: Beatrix Kiddo. As Elle exits the trailer, Beatrix ambushes her and they fight. Elle, who was also taught by Mei, taunts Beatrix by revealing that she poisoned Mei in retribution for his plucking out her eye. Beatrix plucks out Elle's remaining eye and leaves her screaming in the trailer with the black mamba.Beatrix tracks Bill to the Mexican countryside and discovers that their daughter B.B. is still alive, now aged four. She finds her with Bill in a hotel and spends the evening with them. After she puts B.B. to bed, Bill shoots Beatrix with a dart containing truth serum and interrogates her. She recounts a mission in which she discovered she was pregnant, and explains that she left the Deadly Vipers to give B.B. a better life. She disables Bill with the Five Point Palm Exploding Heart Technique, which Mei secretly taught her. Bill makes his peace with her, takes five steps and dies. Beatrix leaves with B.B. to start a new life., Question: How old IS B.B.?
Output (English): Answer: 4