Need with c.
volcanos form when magma forces it’s way up through weak spots in the crust. where are these weak spots?

I'm not sure about the answer that you need help with, but I can help with the answer to question 4.a and b. The ring of fire is an area in the Pacific ocean where lots of volcanic and seismic activity takes place. Volcanic eruptions and earthquakes are common in this area because of the tectonic plate boundaries.