A

Selective incorporation is used in order to ensure the observance of constitutional rights in state laws in the United States.

Explanation:

In the process of creating the U. S. Constitution, there was no restriction of federal powers, and to fix that, the Bill of Rights was designed. However, the Bill of rights applied to the federal government only, and not the state laws. This meant that states could pass laws, which did not observe human rights, listed in the constitution. In order to fix that, the fourteenth amendment was ratified. At first, it only referred to life, liberty and property rights, but was later extended, so that the whole Bill of Rights has effect in all states. This amendment was first applied in the case of Gitlow v. New York in 1925, protecting freedom of speech. After that, some courts relied on the individual protections, mentioned in the Bill of Rights. Selective incorporation definition can be stated as a case-to-case approach, when deciding whether to recognize the constitutional rights or not.

The selective incorporation doctrine implies the states follow the first ten amendments to the constitution. Under this doctrine, the Supreme Court started to partially make allowance for the amendments, not incorporating the whole amendments. To represent full or selective incorporation of the Bill of Rights, Legal Information Institute of the Cornell Law School provides this table:

Full Incorporation Partial Incorporation No Incorporation
First Amendment Fifth Amendment (The right to indictment by a grand jury has not been incorporated) Third Amendment
Second Amendment Sixth Amendment (The right to a jury selected from residents of crime location has not been incorporated) Seventh Amendment
Fourth Amendment Eighth Amendment (Prohibition against excessive fines has not been incorporated)

As for the Ninth and Tenth Amendments, they have not been incorporated, but the former one is rarely taken into consideration in the Supreme Courts, and the latter one directly corresponds with the states’ laws.