Question: Casualty had to be rescheduled on March 30, 2002, due to the death of which wife of King George VI?
Sentence (from "Queen Elizabeth The Queen Mother"): She was Queen of the United Kingdom and the Dominions from her husband's accession in 1936 until his death in 1952, after which she was known as Queen Elizabeth The Queen Mother, to avoid confusion with her daughter.
Relevant evidence: No