Concept:The 1963 Republican Constitution introduced the indirect election of Nigeria’s President.Explanation:Before 1963, Nigeria had a Governor-General representing the British Queen.In 1963, Nigeria became a republic and created the office of President.The President was elected indirectly by members of parliament, including the Senate, through secret ballot.The term of office was five years.The later 1979 Constitution changed to a direct election system.Answer:1963