The presidential system of government was introduced in Nigeria with the Constitution of

The presidential system of government was introduced in Nigeria with the Constitution of 1979. Before this time, Nigeria had operated a parliamentary system of government, but the military government that took power in 1966 abolished this system and ruled the country through a series of military regimes. In 1979, a new civilian government was established and a new constitution was enacted that created a presidential system of government. This system featured a strong executive presidency with a president who serves as both head of state and head of government, and a bicameral legislature consisting of a Senate and a House of Representatives. The 1979 constitution was later amended, and a new constitution was enacted in 1999, which retained the presidential system of government that had been introduced in 1979. So, the correct option is 1979.