The answer is A. and B.
Let's look into the options one by one:
A. pressure and heat built up in the magma chamber
This is true as the pressure and heat built up is what cause the magma to be pushed out of the chamber through the vent. The higher temperature it is,the more it expands and the more likely it is to erupt.
B. plate tectonics and subduction
This is also true as volcanicity is caused by plate tectonics such as subduction. When the plate bends, cracks are formed which coul then be filled by magma and cause fissure eruption, afterwards forming volcanoes.
C. ground swelling and foreshocks
These are the consequences of volcanic eruption but not the causes and therefore is not true.
D. foreshocks and aftershocks
These are as well the consequences of volcanic activity like above and is not true.
Therefore the answers are A. and B.
Hope it helps!
Answer:
b) a subduction boundary
Explanation:
The subduction boundaries, or convergent plate boundaries, are the places where the tectonic plates are colliding, and one of them subducts below the other. As one of the plates moves below the other, there's lot of pressure, and cracking occurring in the crust, so the magma manages to penetrate through it and comes out on the surface with ease. As it manages to get on the surface, it lifts up the land, and creates a cone shaped volcano. This volcanoes manage to make a very nice shape, the stereotypical volcano shape, and that is a result of constant pilling of material on the slopes of it. Some of the volcanoes that are regarded as the most beautiful are actually volcanoes of this type, like Mount Fuji in Japan for example.
Answer : B
Explanation: the change is caused by erosion that is caused by strong ocean waves bashing up against the cliff.
