Question

1. volcanoes happen when

a seafloor spreading travels to the continents.
b erosion exposes magma.
c destructive forces explode.
d tectonic plates collide.

Explanation:

Volcanoes occur mainly when tectonic plates interact. When tectonic plates collide (convergent - plate boundaries), one plate can be forced beneath the other (subduction). This subduction can cause the melting of the sub - ducting plate and the overlying mantle material, forming magma. The magma then rises to the surface through cracks and erupts as a volcano. Seafloor spreading is related to the creation of new oceanic crust and not directly to volcano formation in the way described in option A. Erosion does not typically expose magma in a way that causes volcanoes as described in option B. The term "destructive forces explode" is too vague compared to the well - defined tectonic plate interaction in option D.

Answer:

D. tectonic plates collide