<span>Assuming that this is referring to the same list of options that was posted before with this question, the best answer is the one having to do with the fact that it is "thorough" </span>
The Triangle Shirtwaist Factory Fire showed how important it is to practice fire safety at work. The Triangle Shirtwaist Factory Fire showed how far we have come as a society when it comes to fire and work safety.
The Schengen Visa is appropriate because if you have one, you can travel to every country that is a member of the European Union, and those who aren't but have been granted the Schengen status. By obtaining it once, you can travel anywhere from the list without having to think about visas or borders or anything similar.
