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 $4.40, in which year will commodity X cost 70 cents more than the commodity Y? Choose the correct choice from the following answers:
A) 2010 B) 2011 C) 2012 D) 2013 E) 2014

Rationale: "the cost of commodity x increases by 10 cents per year relative to commodity y . the price of x must gain 20 + 70 = 90 cents on commodity y , which will take 9 years . the answer is a ."
Answer: A