Q:Extract the answer to the following question from the movie plot. If the question isn't answerable, please output "Can't answer". Question: Who asks Jo to sing? Title: The Man Who Knew Too Much Movie plot: An American familyDr. Benjamin "Ben" McKenna (James Stewart), his wife, popular singer Josephine Conway "Jo" McKenna (Doris Day), and their son Henry "Hank" McKenna (Christopher Olsen)are vacationing in Morocco. Traveling from Casablanca to Marrakesh, they meet Frenchman Louis Bernard (Daniel Gelin). He seems friendly, but Jo is suspicious of his many questions and evasive answers. Louis offers to take the McKennas out to dinner, but cancels when a sinister-looking man knocks at the McKennas' hotel-room door. Later, at a local restaurant, the McKennas meet friendly English couple Lucy (Brenda De Banzie) and Edward Drayton (Bernard Miles). The McKennas are surprised to see Bernard arrive and sit at another table, apparently ignoring them. The next day, attending a busy outdoor market with the Draytons, the McKennas see a man being chased by police. After being stabbed in the back, the man approaches Ben, who discovers it is actually Louis in disguise. The dying Bernard whispers that a foreign statesman will be assassinated in London soon, and that Ben must tell the authorities there about "Ambrose Chappell". Lucy offers to return Hank to the hotel while the police question Ben and Jo. An officer explains that Louis was a French Intelligence agent on assignment in Morocco. Ben is told via a phone call that Hank has been kidnapped but will not be harmed if the McKennas say nothing to the police about Bernard's warning. In London, Scotland Yard's Inspector Buchanan (Ralph Truman) tells them Louis was trying to uncover an assassination plot, and that they should contact him if they hear from the kidnappers. Leaving friends in their hotel suite, the McKennas search for a man named "Ambrose Chappell" and find "Ambrose Chapel", where Drayton is leading a service. Ben confronts Drayton and is knocked out and locked in the chapel. The Draytons take Hank to a foreign embassy just before Jo arrives with police at the now-deserted chapel. Jo learns that Buchanan has gone to a concert at the Royal Albert Hall. There,...
A:
The Prime Minister