Bimetallism is the monetary policy based on the use of two metals, as legal tender without limit and equalized by law in a fixed ratio. Which are these two metals?

 Bimetallism is the monetary policy based on the use of two metals, as legal tender without limit and equalized by law in a fixed ratio. Which are these two metals? 

(a) Platinum and Gold 

(b) Gold and Silver 

(c) Platinum and Silver 

(d) All of the above

Right Answer is (b)