Could somehow know the arc of the sun in the sky and perform spherical geometry to compensate. If use this, the error over the few minutes spent unloading her food and dancing to recruit others would not be very great. Could remember the rate of movement of the sun when they entered the hive and extrapolate from this. Best time to compare the hypotheses is around noon of the summer solstice, June 22, when the sun is moving its fastest. Mimics conditions on a rainy day.
Foragers can come into the hive, but none can get out.
Wait 2 hours, open the hive, and see where the bees go. Results in figure on the right. Can't be preprogrammed because bees can't adjust to the change if moved from one hemisphere to another. C. Polarized light orientation. Run to ocean where safe when danger threatens.