Задайте вопросы к предложению : she has been flying over the ocean for 3 hours. a) yes/no; b) where (how long); c) who

A). Has she been flying over the ocean for 3 hours?
b) How long has she been flying over the ocean?
Where has she been flying for 3 hours?
с) Who has been flying over the ocean for 3 hours?