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.

Example Input: Passage: In 2004, a large share of natural gas reserves in Iran were untapped. The addition of new hydroelectric stations and the streamlining of conventional coal and oil-fired stations increased installed capacity to 33,000 megawatts. Of that amount, about 75% was based on natural gas, 18% on oil, and 7% on hydroelectric power. In 2004, Iran opened its first wind-powered and geothermal plants, and the first solar thermal plant is to come online in 2009. Iran is the third country in the world to have developed GTL technology. Question: How much of Iran's 33k megawatt installed capacity was based on oil? 
Example Output: 18%

Example Input: 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?
Example Output: Congress for Progressive Change

Example Input: Passage: In 1986, the Compact of Free Association with the United States entered into force, granting the Republic of the Marshall Islands (RMI) its sovereignty. The Compact provided for aid and U.S. defense of the islands in exchange for continued U.S. military use of the missile testing range at Kwajalein Atoll. The independence procedure was formally completed under international law in 1990, when the UN officially ended the Trusteeship status pursuant to Security Council Resolution 683. Question: What document granted sovereignty to the Marshall Islands?
Example Output:
the Compact of Free Association