Question id 22 - Air Law - Quiz BPL Gas - Balloon Pilot License

Height of the base of the highest layer of clouds covering more than half of the sky below 20000 ft
Height of the base of the lowest layer of clouds covering more than half of the sky below 10000 ft
Altitude of the base of the lowest layer of clouds covering more than half of the sky below 20000 ft.
Height of the base of the lowest layer of clouds covering more than half of the sky below 20000 ft.