To change or improve something by correcting faults or removing abuses is to
a: react
b: reform
c: repeat
d: repeal

The correct answer is B. Reform.

The most important reforms were given during the progressive era. Another well-known reform was the protestant reformation which was started by Martin Luther. This guy posted in the wall of the Wittenberg Castle Church, 95 theses and with that started the protestant reform.

He led the transcendentalist movement.