Among the People Who Are Characterized Below, Who Has the Highest

Among the people who are characterized below, who has the highest opportunity cost of leisure?

A) a veterinarian who earns $25 per hour and who goes surfing during her leisure time
B) a professional tennis player who earns $50 per hour giving tennis lessons and who watches TV during his leisure time
C) a retail clerk who earns $15 per hour and who plays computer games during his leisure time
D) a CPA who earns $150 per hour and who golfs during her leisure time