(a) whether the Government has allowed all the private developers to levy and collect airport development fee from the passengers and if so, the details thereof;
(b) whether the User Development Fee being charged at various airports in the country is very high, especially at Delhi Airport and if so, the details thereof;
(c) whether the Government has asked the Airports Economic Regulatory Authority (AERA) to review the airport charges; and
(d) if so, the details thereof along with the action taken so far by AERA in this regard?