This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.
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Question: Passage: Goodluck Jonathan served as Nigeria's president till 16 April 2011, when a new presidential election in Nigeria was conducted. Jonathan of the PDP was declared the winner on 19 April 2011, having won the election with a total of 22,495,187 of the 39,469,484 votes cast, to stand ahead of Muhammadu Buhari from the main opposition party, the Congress for Progressive Change (CPC), which won 12,214,853 of the total votes cast. The international media reported the elections as having run smoothly with relatively little violence or voter fraud, in contrast to previous elections. Question: What was the main opposition political party in 2011?

Answer: Congress for Progressive Change

Question: Passage: Meanwhile, Kerry's staff began their own investigations and, on October 14, issued a report that exposed illegal activities on the part of Lieutenant Colonel Oliver North, who had set up a private network involving the National Security Council and the CIA to deliver military equipment to right-wing Nicaraguan rebels (Contras). In effect, North and certain members of the President's administration were accused by Kerry's report of illegally funding and supplying armed militants without the authorization of Congress. Kerry's staff investigation, based on a year-long inquiry and interviews with fifty unnamed sources, is said to raise "serious questions about whether the United States has abided by the law in its handling of the contras over the past three years." Question: Who had Oliver North been supporting?

Answer: right-wing Nicaraguan rebels (Contras)

Question: Passage: Within Shia Islam (Shiism), the various sects came into being because they differed over their Imams' successions, just as the Shia - Sunni separation within Islam itself had come into being from the dispute that had arisen over the succession to Muhammad. Each succession dispute brought forth a different tariqah (literal meaning 'path'; extended meaning 'sect') within Shia Islam. Each Shia tariqah followed its own particular Imam's dynasty, thus resulting in different numbers of Imams for each particular Shia tariqah. When the dynastic line of the separating successor Imam ended with no heir to succeed him, then either he (the last Imam) or his unborn successor was believed to have gone into concealment, that is, The Occultation. Question: What is it called when the last Imam or his unborn successor goes into concealment?

Answer:
The Occultation