Arnold Kim began blogging about Apple products during his fourth year of medical school. Kim's Website, MacRumors.com, became so successful that he decided to give up his medical career and work full time on his Website, despite the nearly $200,000 he had invested in his education. In making his decision, the $200,000 he spent on his education O a. should be ignored since it represents a sunk cost. O b. should be considered since it is money he has spent and needs to recoup. O C. should be ignored only if Kim can earn more than $200,000 by running his Website. O d. should be considered since it is money he could have used to invest in his Website.