Aresearcher concludes that frustrating people by giving them a task that is impossible to complete causes them to behave more aggressively. only warrants this type of conclusion.

The correct answer is: Experimental research  

Explanation:

Experimental research is a technique or an experimental procedure research which is performed or conducted to validate or support a hypothesis. In this scientific approach, a particular set of variables are observed and measured by keeping other set of variables constant, as a subject of the research or the experiment.

not  

cuba  

russia  

iraq  

el salvador  

explanation:

known as the land of volcanoes, el salvador has visit seismic tremors and volcanic movement. it is the main nation in central america that does not have a coastline on the caribbean sea. about portion of all salvadorans live in the wide open. they are poor and don't have power or running water in their homes. in 1525, pedro de alvarado, a lieutenant of cortés's, vanquished el salvador. el salvador, with alternate nations of central america, pronounced its freedom from spain on sept. 15, 1821, and was a piece of a league of central american states until the point when that association broke up in 1838.

answer; substantive law;