In permanent mould casting method

• A. olten metal is poured in a metallic mould, retained in the mould long enough for the outer skin to solidify and finally mould is turned over to remove molten metal still in molten condition
• B. olten metal is poured and allowed to solidify while the mould is revolving
• C. olten metal is forced into mould under high pressure
• D. one of the above