Researchers experimentally manipulated the circadian rhythm of monarch butterflies, a migratory butterfly, by housing individuals in a room in which the light and dark cycle was shifted backward by six hours, meaning that the lights came on at 12:00 AM (midnight) and went off at 12:00 PM (noon). The subjects were kept in this room for a week, during which time their circadian rhythms adjusted to the shifted light and dark cycle.
Assume that the natural light cycle (before experimental manipulation) is from 6:00 AM to 6:00 PM and that we are in the Northern Hemisphere. You may also assume that, during the time of year in which this experiment was performed, monarch butterflies would use the position of the sun throughout the day to orient themselves in a southerly direction. For example, at the midpoint of their light cycle (noon for the control subjects) they would fly directly toward the sun, because it is in the south at this time. The clock-shifted subjects were then released at 6:00 AM in the natural morning.
Given that these subjects' subjective day began at 12:00 AM (midnight) and ended at 12:00 PM (noon), in what direction would they fly when released? (Hint: Think about the time of day the subjects will think it is.)

North
East
West
South