Answer:
a. press the button and "shoot" the black young men, regardless of what they were holding.
Explanation:
This research is a racial profiling study. After the shooting of Amadou Diallo in 1999 and subsequent cases of shooting of innocent black males by the police force, several studies were carried out to investigate racial profiling. In the study in the question above, the participants were more likely to press and shoot the young black men regardless of what they were holding. This is an example of racial profiling.
The EU is a political and economic union of 28 countries, which developed an internal single market through a standardised system of laws. Politically, these 28 countries are linked by the European Parliament, the European Commission, the Council of Europe and the European Council (the last two have similar names, but they have different functionalities). Economically, by the ECB - the European Central Bank. Monetarily, by the Eurozone and the currency EURO, which is present in 19/28 countries. Also, there's a Schengen area, where passports are abolished and you can travel freely, BUT not all the countries that are in the EU, are in Schengen area (ex. Romania, Bulgaria); and vice-versa: Norway is not in the EU, but is part of the Schengen area.
I hope I helped, I used to have a "map" of interactions of all these countries in different unions/institutions, but cannot find it. If you need one to help you understand the EU better, tell me and I'll intensively look for it!
Update: here's the map.
East because it is going across the Atlantic ocean