Rare Coins is going to sell 5,000 "common" $20 gold coins in July. The company would like to hedge this transaction using the following available futures. The company has collected the regression result of common $20 gold coin price on each futures price as below. Futures on gold: SGc-350+1.5FG, R-0.78 Futures on platinum: SGc= 50+0.5Fp, R-0.82 Futures on silver coin: SGc= 128+23Fsc. R-0.85 Which is the best contract the company should use to hedge?