The correct answer is d. Fault. When a player serves the ball outside the service box, it is considered a fault. To arrive at this answer, we can rely on our knowledge of tennis rules or consult a reliable source such as the official rulebook of the sport. Tennis rules define a fault as a failed attempt to serve the ball within the correct service box. This results in loss of a point and a second serve opportunity (or loss of the serve entirely, depending on the specific rules being followed).
