Answer:
The map labeled with 1 shows the major plate boundaries and where most of the earthquakes and volcanoes occur.
Step-by-step explanation:
The map labeled with number 1 is showing us the plate boundaries. This can easily be confirmed as the lines that are drawn are in the exact same places where the plate boundaries are located. The plate boundaries are the places that are tectonically the most active on Earth, with earhtquakes and volcanoes being a regular occurrence.
Not all plate boundaries though have around the same intensity of earthquakes or number of volcanoes. This is due to the difference in plate boundaries. At the convergent plate boundaries (depending is it between two continental, continental and oceanic, or two oceanic) there can be the formation of volcanoes or mountain ranges, with earthquake activity varying a lot. At transform boundaries, there isn't volcanic activity but there are a lot of earthquakes. At divergent boundaries, earthquakes are rare, but there is intense and constant volcanic activity.