A policy of extending a nation power by gaining political and economic control over other nation.
The Case Study Method is the correct answer.
The research plan Jamie chooses to identify what experiences may contribute to children's hyperactivity is referred to as the case study method. A case study method is a deeper analysis of one person's behavior (or a small number of people's) that allows the researcher to obtain more details and also to reconstruct the 'case history' of a participant.