Many of the islands of Indonesia (Java, Sumatra, Borneo), which are located adjacent to a subduction zone next to the edge of the continental shelf of SE Asia, consist of felsiclava. This means that the lava that produces these islands is derived from
A) a midocean ridge.
B) a volcanic hot spot under the ocean floor.
C) the melting of continental shelf material along with ocean floor material.
D) the melting of subducted plate material and nothing else.
E) a rift zone