A passenger in an aeroplane shall:

1. never see a rainbow.

2. may see a primary and a secondary rainbow as concentric circles.

3. may see a primary and a secondary rainbow as concentric arcs.

4. never see a secondary rainbow.

(2) Hint: The visibility of a rainbow depends on the position of the perosn.

A passenger in an aeroplane may see primary and secondary rainbow-like concentric circles.