'Gold Bullion Standard refers to:

 a) gold coin as an unlimited legal tender
 b) gold as the measure of value
 c) free coinage of gold
 d) no restriction on import and export of gold

SSC-2015

gold as the measure of value. The gold bullion standard is a system in which gold coins do not circulate, but the authorities agree to sell gold bullion on demand at a fixed price in exchange for the circulating currency.