The correct options are
A The study of past, present and future of political institutions, political functions and political theories
B The study of state, government and human political activities
D Study of origin, development, nature, scope, political functions and political theories
There are many ways to define political science. Political science is the study of state, government and human political activities.
It also includes the study of constitution and law. But this definition excludes other important issues covered under political science.