In this task, you're expected to write answers to questions involving multiple references to the same entity. The answer to the question should be unambiguous and a phrase in the paragraph. Most questions can have only one correct answer.
One example is below.
Q: Passage: Nearing London, Oliver encounters Jack Dawkins, a pickpocket more commonly known by the nickname the "Artful Dodger", and his sidekick, a boy of a humorous nature named Charley Bates, but Oliver's innocent and trusting nature fails to see any dishonesty in their actions. The Dodger provides Oliver with a free meal and tells him of a gentleman in London who will "give him lodgings for nothing, and never ask for change". Grateful for the unexpected assistance, Oliver follows the Dodger to the "old gentleman's" residence. In this way Oliver unwittingly falls in with an infamous Jewish criminal known as Fagin, the gentleman of whom the Artful Dodger spoke. Ensnared, Oliver lives with Fagin and his gang of juvenile pickpockets in their lair at Saffron Hill for some time, unaware of their criminal occupations. He believes they make wallets and handkerchiefs. 
Question: Who believes Fagin's gang make wallets and handkerchiefs?
A: Oliver.
Rationale: In the sentence "He believes they make wallets and handkerchiefs", the pronoun "he" refers to name "Oliver".
Q: Passage: Arthur Harris is the grumpy husband of Marion, who is terminally ill yet continues to participate with enthusiasm at her local seniors' choir, The OAP'Z. The choirmaster is a young teacher, Elizabeth who is preparing the choir to enter a local musical choir competition called "Shadow Song". Arthur is also estranged from his son, James. Marion's health deteriorates over time until one night when she dies in her sleep. Arthur initially takes this loss severely and cuts himself from his family and the choir. Eventually he agrees to take Marion's place in the choir. The transition proves to be a challenge for Arthur thanks to the unconventional songbook that includes racier songs such as Salt-N-Pepa's "Let's Talk About Sex" and Motorhead's "Ace of Spades". However he grows to enjoy spending time in the choir.
On the eve of the competition, Arthur has an argument with James in a failed attempt to rebuild their relationship and pulls out of the choir. The choir participates in the competition without Arthur. He arrives later but before he can perform with the choir, they are eliminated from the competition by the judges. The choir are on their way to return home in defeat when Arthur stops the bus and storms the musical competition's stage shortly joined by the rest of the choir. They perform again with Arthur singing a solo of "Lullabye (Goodnight, My Angel)". The choir finishes in third place and returns home triumphant. Arthur and his son, James (who watched him perform in the competition) reconnect on the journey home with James leaving an answering phone message confirming this later. 
Question: Who is the estranged son's mother's choir teacher?
A:
Elizabeth.