please choose USD PM (Gold Fixing Price at 3:00 P.M. (London time) in London Bullion Market, based in U.S. Dollars).
PS. I am not Quandl employee. I share this because I am kind. BTW, have fun.
the LBMA fixings are not the assets of the competition, the fixings are not taking into consideration the rolling price of the futures or the storage costs of gold and are thus uninvestible assets, their returns are highly correlated with the BBs.