Differences in temperature, pressure, and structural formations in the mantle and crust cause magma to form in different ways. Decompression melting involves the upward movement of Earth's mostly-solid mantle. This hot material rises to an area of lower pressure through the process of convection.
Either B) increased parasympathetic stimulation of the heart. OR D) Constriction of elastic arteries to maintain blood pressure. I'm leaning more towards D) constriction of elastic arteries to maintain blood pressure.