Concept:Nigeria's Second Republic from 1979 to 1983 used the presidential system of government.
Explanation:During this period, the Constitution created an executive President.
The President served as both head of state and head of government.
The executive was separate from the legislature, following the American model.
This system replaced the parliamentary system used in the First Republic.
Therefore, the correct option is the presidential system of government.
Answer:B. Presidential system of government