Respuesta :
Diamonds cam form in the mantle because of the impact of the weight of the overlying rock which bears down on it, in combination with the high temperature of the area where they are formed (about 100 miles beneath the surface). Therefore, the correct answer is option D. The weight of the rocks above the mantle results in high pressure.
Diamonds need high temperatures and pressure to form from carbon. Diamonds form in the mantle in certain zones where conditions are right for them to do so. There just happens to be the right critical temperature- pressure mineral environment in the mantle in certain zones for their formation. I think the answer Is A.