Shell molding is best described by which one of the following:

• A. casting process in which the mold is a thin shell of sand binded by a thermosetting resin
• B. casting operation in which the molten metal has been poured out after a thin shell has been solidified in the mold
• C. casting operation used to make artificial sea shells?
• D. sand casting operation in which the pattern is a shell rather than a solid form