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.
Q: Passage: Guinea-Bissau has started to show some economic advances after a pact of stability was signed by the main political parties of the country, leading to an IMF-backed structural reform program. The key challenges for the country in the period ahead are to achieve fiscal discipline, rebuild public administration, improve the economic climate for private investment, and promote economic diversification. After the country became independent from Portugal in 1974 due to the Portuguese Colonial War and the Carnation Revolution, the rapid exodus of the Portuguese civilian, military, and political authorities resulted in considerable damage to the country's economic infrastructure, social order, and standard of living. Question: What country left Guinea-Bissau in 1974?
A:
Portugal