Concept:Identify the exact duration Murtala Muhammed spent in office and the leader of the coup that killed him.Explanation:Murtala Muhammed became Head of State on July 29, 1975.He was assassinated on February 13, 1976.The period between these dates is approximately 200 days.His assassination happened during an abortive coup led by Lieutenant Colonel Buka Suka Dimka.Therefore, the correct match is 200 days and Lt. Colonel Dimka.Answer:Option D: 200 days / Lt. Colonel Dimka.