Four clocks are drawn below, each with an orange marker at 12. Which clock looks exactly the same when it is seen in an upright mirror?

A clock is unchanged in a mirror only if both hands lie on the vertical 12-6 line. At 6:00 the hour hand is exactly on 6 and the minute hand on 12. At 3:00 the hour hand points right and would point left in the mirror; at 9:30 and 12:30 the hour hand is midway between two numbers, so it moves to the other side.