Answer: Option (3)
Explanation: Zones of crustal activity is also known as the tectonic activities. This is the region, where plates undergoes convergent, divergent or transform movement.
These volcanoes are formed when plates undergoes collision, that means convergent plate boundary, where the denser plate gets subducted beneath the less denser plate.
And the data collected by studying about the different volcanoes, helped in the determining that the volcanoes are mostly located at the zone where crustal activities constantly goes on.
Thus, the correct answer is option (3).