All fronts were important in determining the outcome of the First World War. What was the role of Q ships?

One mark for each relevant point.
Responses may include the following:
- They were used to combat the German U-boat threat.
- Warships were disguised as merchant ships.
- They sailed under false colours and had hidden guns.
- They were used to lure U-boats to the surface.
- They open fired on U-boats as they surfaced.
- Their aim was to destroy German U-boats.