Task: Text Categorization
Input (English): Question: An Au-Ag alloy: 
 Options:  <0> It is interstitial, and can occur in any composition. <1> It is substitutional, and can occur in any composition. <2> Gold and silver can not be alloyed. <3> A small amount of gold can be dissolved in silver, up to a limit of close to 10%, but not in a greater proportion. <4> A small amount of silver can be dissolved in the gold, up to a limit close to 10%, but not in a greater proportion.
Output (English): chemistry