Task: Question Answering
Input (English): Problem: the price of commodity x increases by 30 cents every year , while the price of commodity y increases by 20 cents every year . if in 2001 , the price of commodity x was $ 4.20 and the price of commodity y was $ 4.50 , in which year will commodity x cost 90 cents more than the commodity y ? 
Options: a ) 2010 , b ) 2011 , c ) 2012 , d ) 2013 , e ) 2014
Output (English): d