In a hypothetical cross-sectional study, marriage was found to be strongly associated with increased levels of happiness. Authors concluded that marriage was a cause of happiness. However, a reviewer of this study argued that because it is a cross-sectional study, it could not be determined whether marriage caused happiness or happiness caused marriage. What criterion of causal relationships was not met in the study according to the reviewer

The correct answer is - temporal relationship.

Explanation:

Temporal relationship is the timing between a variable or factor and an outcome or result that can be used to assign a reason for the relationship. This type of causal relationship that is temporal relationship cannot be assessed in a cross-sectional study.

As it can not be assessed in the cross-sectional study so, it is not possible to assess if happy people are more likely to get married or marriage leads to happiness.

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.

explanation:

allergens: overstimulate the nerve system

neurotics: attack nerve cells

mutagens: damage or otherwise alter dna sequence

generators: cause defects during growth and development  

carcinogens: cause unchecked cell growth

i hope you get the idea according to me these are the effects that happened.