In this task, you're given a passage, further information available on a particular linked term from the statement, and an answer term. Your job is to generate a question that can use the information provided to obtain the given answer. You should use the information on both passage and link information to create the question. Note that the answer to the question should be exactly the given answer, and if the answer is none, the answer to the question shouldn't be obtainable from the passage or linked information.
Q: Passage: His credential and reputation eventually led him secure nomination for the presidency by Prime Minister Benazir Bhutto and elected as President in 1993. However, he began receiving criticism over the controversial appointments of Senior Justices of the Supreme Court of Pakistan and was implicated in Mehran Bank scandal. Differences began to emerge with Prime Minister Benazir Bhutto on policy issues in 1995 and he surprisingly dismissed his leader's government in 1996. His political ambitions later clashed with Prime Minister Nawaz Sharif and his intervention to retain Justice Sajjad Ali Shah as Chief Justice finally led to his resignation in 1997. He remained active in politics and joined the PML(Q) in 2004. Leghari died from a long heart illness at the Combined Military Hospital in Rawalpindi on 20 October 2010.
Link Information: Nawaz Sharif became the 12th Prime Minister of Pakistan on 1 November 1990 Answer: 1990
A:
What year did Sharif become Prime Minister?