Paul just found out that he got a grade of "D" (poor) on his economics class midterm. Which of the following responses by Paul would best illustrate a self-serving bias? Group of answer choices "Wow, I studied the right content, but I still got most of the answers wrong." "I guess I'm not good at understanding economics" "I knew the material, but this was an unfair, tricky test." "I can't believe it; I studied really hard for this test