You will be given a definition of a task first, then some input of the task.
This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.

Passage: On 12 January 1953, he was appointed Patriarch of Venice and, accordingly, raised to the rank of Cardinal-Priest of Santa Prisca by Pope Pius XII. Roncalli left France for Venice on 23 February 1953 stopping briefly in Milan and then to Rome. On 15 March 1953, he took possession of his new diocese in Venice. As a sign of his esteem, the President of France, Vincent Auriol, claimed the ancient privilege possessed by French monarchs and bestowed the red biretta on Roncalli at a ceremony in the Elysee Palace. It was around this time that he, with the aid of Monsignor Bruno Heim, formed his coat of arms with a lion of Saint Mark on a white ground. Auriol also awarded Roncalli three months later with the award of Commander of the Legion of Honour.
Output:
When was Pope Pius XII appointed Patriarch of Venice?