b) To provide weapons for slaves who joined his movement.
Explanation:
John Brown was an abolitionist who advocated for the use of arms in fighting the slavery system. His immense hatred of the system led him to recruit fighters who will help him in his cause.
John Brown along with some followers of him raided the Harper's Ferry, a federal armor facility with the intention of getting arms to give to the slaves who joined his movement. Though this raid was partly successful, it also led to the death of seven people. And his intention of recruiting and arming more people did not turn up well like he intended to, with only a few people coming to him.
