Question: Usman Mu'azu was the governor of Kaduna State during the reign of the military leader who became President of Nigeria in what year?
Sentence (from "Muhammadu Buhari"): Muhammadu Buhari {'1': ", '2': ", '3': 'GCFR', '4': "} (born 17 December 1942) is the President of Nigeria, in office since 2015.
Relevant evidence: Yes