John lives 3 blocks west and 3 blocks south of the southwest corner of a large plaza. His office is 1 block east and 2 blocks north of the northeast corner of the same plaza. On workdays, he walks on streets to the southwest corner of the plaza, then takes a diagonal path through the plaza to the northeast corner, and then walks on streets to his office. If his route is as short as possible, how many different routes can he take?
48
54
60
66
72
