Mark went to the pet store to get a puppy. He had only $25 and to his dismay all puppies for sale were more than $100. He tried to negotiate, but the shopkeeper denied his request. As he was about to leave, he saw a puppy limping at the counter. Upon enquiry, the shopkeeper was willing to give it to Mark for FREE as it had a hip problem & couldn't run. Mark disappointedly looked at the shopkeeper and rolled his pants up and showed his left leg that was in steel braces. What thoughts do you think must be going on in Mark's head?