Which best explains how the idea of non-violent protest has changed since thoreau?
it has adapted to the needs of those working for change.
it has become less and less aggressive and confrontational.
it has given people more chance to object to government.
it has taken fewer and fewer risks with people's lives.

It has become less and less aggressive and confrontational

Henry David Thoreau's essay Resistance to Civil Government or briefly known as Civil Disobedience, is an essay. It is a revolutionary form of essay writing. 
There are several factors that propelled Thoreau to write this essay, some of which were slavery and the Mexican-American war. He wanted to make the people realise how the governments were manipulating them and overruling their consciences. 

Inform should be the answer