Concept: Determine the duration of the Nigerian Civil War using its known start and end dates.Explanation:The Nigerian Civil War began on 6 July 1967.It ended on 15 January 1970.This period covers 2 years and 6 months.Since 2 years equals 24 months, adding 6 months gives 24+6=30 months.Therefore, the war lasted exactly 30 months.Answer: C. 30 months