Sostre was believed to have been producing molotovs in his basement and organizing looting and arson and similar things so they arrested him. He was eventually moved to a different prison which enabled him to contact his lawyers more and the case developed and people started polarizing over the idea of whether he was a good guy or a bad guy.
This site will probably help you, hope this help.
http://www.shmoop.com/esperanza-rising/marta.html
The answer is A. a plan to rebuild the south