Quiz: "guns" or "arms"?

The correct answer is: arms

Teachers and parents are up in arms over the cancellation of the school building scheme.

If people are up in arms, they are very angry about something. Here the word "arms" means weapons. In the Middle Ages, the term referred to an armed rebellion or conflict. Now the term is used figuratively to describe someone who is very angry. 

Parents and teachers in the UK are up in arms because the new Coalition government has decided to scrap the Building Schools for the Future programme. The scheme was introduced by the previous Labour government in 2004 because so many British schools were in a terrible state of disrepair, often lacking adequate heating or air-conditioning. About 180 schools have been renovated so far, but now the Conservative and Liberal Democratic Coalition is axing the scheme. They feel it is "unnecessarily overbureaucratic" and has been massively overspending. Over 720 schools that had invested time and money into planning new buildings have been told their redevelopments will not go ahead. This week, angry parents, teachers and students from all over the country marched on the streets of London to protest against the plans.

be up in arms = Sturm laufen, empört sein