The correct answer is indeed option C. "A rebellion in Scotland weakened the king, who was suspected of supporting the rebels". The civil war in England took place between the supporters of the monarchy of Charles I and his son Charles II and opposing groups in each of Charles’s kingdoms, including English Parliamentarians and Covenanters in Scotland. The previous victory of Covenanters during their rebellion in Scotland was one of the main reasons that led to England's civil war.
When more then half of a group decides on a subject or issue
Ideally, it should intervene when the benefits are higher then costs- i believe that "higher" is the correct answer here. If the benefits are higher than costs, generally an action make sense (but whether this is always the case depends whether the government is efficient...)
