Where can volcanoes form a. Only at plate boundaries b. Only in the middle of plates c. At either plate boundaries or in the middle of plates

c. At either plate boundaries or in the middle of plates

Explanation:

Most of the volcanoes, cercad and 60% are formed at the ends of the tectonic plates, mainly during the moments where they collide, causing deformities in the geography of the earth. However, a few volcanoes can appear in the middle of the technical plates, through the hot spots, which can suggest well inside the plate.

d. new methods of assembly are introduced.

explanation:

this allows for the goods to be made on a larger scale. not faster because now it is shown to be made better, hence the greater productivity in the question. it is calling for something new to be introduced.