What country has the most active valcanoes in the world?
Indonesia has the most volcanoes in the world.  They currently have more than 140 located in an area call the Pacific Ring of Fire, around 76 of them are active volcanoes.  Active volcanoes can be very dangerous because they can erupt at any time, and predicting when they will erupt is an on-going science that scientists hope to be able to achieve with increased latency in order to save lives.