The correct answer to this question would be alternative B)"Their beliefs about baptism made other groups see them as a threat to traditional order."
Anabaptists believe that baptism is only valid when the individual confesses their faith in Christ and really wants to be baptized, otherwise, the baptism would be invalid.
This greatly differs from the beliefs of both Protestants and Catholics, that believe that christians should be baptized as early as possible. The Anabaptists' beliefs were a threat to traditional order.