The correct answer is D.
Specie means metallic money it all its forms. Initially it was used to describe gold and silver coins only, later nickel and copper were also included. It was a form of metallic money ( never notes) in the past.
The term 'specie' comes from 16th century Latin and it is an ablative of 'species' which mean 'form, kind, in the actual form'.
This term is also applied to gold and silver bullion ( ordinary gold and silver, without collectible value).
Since January 1934, the gold coin is no more coined by the U.S. government.