Answer:
String of small volcanic islands most likely form at convergent ocean-ocean boundary .
Step-by-step explanation:
When an oceanic tectonic plate undergoes subduction beneath another oceanic tectonic plate, giving rise to a ridge formed between the two oceanic crusts, molten magma rises from the mantle and erupts through the boundaries of the ocean crust.
This causes a large amount of lava to deposit on the ocean floor. Eventually, the accumulated lava rises over the sea level forming an island over many years. Sometimes through this process of convergence and subduction, a whole chain of volcanic islands is formed and this type of string of volcanic islands is called volcanic arcs.