Monroe doctrine
a. what was it?

James Monroe made a policy known as the Monroe Doctrine in 1823. A doctrine is just a set of beliefs or rules. It said that the United States of America wouldn't allow European nations to send armies to the countries that are located in the Western Hemisphere. The Monroe Doctrine still stands as of today.

depends on the age of the teen, many believe by the age of 16 a person should know the strong difference between right and wrong along with the difference between risky and immediate death. swimming with sharks might be dangerous but swimming with sharks while bloody meat is attached to you is just insane. even more if you have no idea what you're doing. however, no matter the age, as long as the person is skilled enough and has the mental and physical capacity to control their actions doing whatever sport they put their mind to is all that matters.