someone who supports extreme changes in a society is a\nliberal.\nradical.\njacobin.\nconservative.

Answer:

B. radical

Brief Explanations:

In social - science context, a radical is one who supports extreme changes in society. Liberals generally advocate for more moderate social change. Jacobins were a specific radical political group in the French Revolution, but the term "radical" is a more general term for those seeking extreme social change. Conservatives oppose significant change.