How were the Monroe Doctrine and the Adams-Onis Treaty similar?

Both were treaties which protected Native American lands.

Both were reasons for the war between the U. S. and Mexico.

Both were actions to expand borders and U. S. influence.

Both were agreements signed between the U. S. and Spain.

The correct answer here is the third option. Both of these were instrumental for increasing the territory and the influence of the United States. The Monroe Doctrine may seem paradoxical as it is an isolationist doctrine, but in fact it increased the American influence. With this the US promised to stay away from the affairs of the European nations but it will not tolerate their interference in the affairs of the western hemisphere and the countries there. So, with this the US expanded their influence to the who hemisphere. The Adams-Otis treaty expended the American territories as it was a treaty by which the United States acquired Florida.

The correct answer is the third one