Really Fast Delivery Services has the collected the following information about operating expenditures for its delivery truck fleet for the past five years: Year Miles Operating Costs 2009 110,000 $390,000 2010 140,000 $420,000 2011 100,000 $360,000 2012 130,000 $410,000 2013 170,000 $450,000 What is the best estimate of total operating expenses for 2014 using the high-low method based on total expected miles of 120,000? Select one: a. $402,000 b. $390,000 c. $392,000 d. $385,800