Observers A and B are both at rest in the Earth reference frame, in different parts of a large city, awaiting the start of a fireworks show. They want to synchronize their atomic clocks for some experiments to be conducted later that evening. A and B plan to start their clock displays at an agreed signal, so each clock display is preset to exactly 10:00 p.m., but they will not record time until the "start" buttons are pressed. Observer A suggests that each of them start upon seeing the first firework, and observer B suggests that each of them start upon hearing the first firework.

(a) Which plan leads to the clocks being more closely synchronized, and why?

(b) Is it possible for the two methods to give the same agreement between clocks?