Shoot I’m not from Minnesota :/
The thing responsible for the plate motion is plate tectonics.
They are brought from colder regions e.g. the North and South poles where ice caps are melting to give cold water. Currents are due to the effect of wind on the water.
Answer:
A. are brought from the mantle to the surface in magma that hardens into kimberlite
Explanation:
Diamonds are brought to the surface from the mantle in a magma that is known as the kimberlite. This kimberlites is rich in gases and it is an igneous rock that has the following minerals,olivine, phlogophite, serpentine etc.
The origination of diamonds in the mantle happens as carbon transformation occurs due to heat and pressure occurs. The kimberlite pipes and what brings the diamonds to the surface