Agroup of researchers is measuring foot traffic in a museum. recently one half of the museum was redone in order to encourage more foot traffic. researchers are counting the number of attendees in this new zone and comparing it to other zones that have not been redone. on the first day that researchers are recording foot traffic, several buses of schoolchildren arrive at the museum unexpectedly for a field trip. after a day of testing, the new zone appears to be getting just as much foot traffic as the other zones. which problem is most likely affecting this quasi-experiment?
history threat
testing threat
maturation threat
selection threat

history threat

Explanation:

Based on the information provided within the question it can be said that the problem that is most likely affecting this experiment is history threat. This term refers to the way groups differ based on history events. Since the groups that arrived the first day wanted to see something new, once they did foot traffic lowered to normal levels because those people have already seen the museum.

the best answer is b.

hope this : )

trade regulation is a field of law, often bracketed with antitrust (as in the phrase “antitrust and trade regulation law”), including government regulation of unfair methods of competition and unfair or deceptive business acts or practices. antitrust law is often considered a subset of trade regulation law. franchise and distribution law, consumer protection law, and advertising law are sometimes considered parts of trade regulation law.

in general the theory of economics says that the more open to trade a country is the better   the result for the same country and the whole economies.

in real life countries impose taxes, quotas, etc which is not so good for the economies.

this kind of commercial war between the usa and china is slowing down the growth of the whole world so we can say that it is a draw back of trade regulations. and the free trade agreements are benefits of trade regulations.