Which of the following are the functions of the Authority under the Airport Authority of India Act?

Section 12.   Functions of the Authority: (1) Subject to the rules, if any, made by the Central Government in this behalf, it shall be the function of the Authority to manage the airports, the civil enclaves and the aeronautical communication stations efficiently.(2) It shall be the duty of the Authority to provide air traffic service and air transport service at any airport and civil enclaves.(3) Without prejudice to the generality of the provisions contained in sub-sections (1) and (2), the Authority may--(a) plan, develop, construct and maintain runways, taxiways, aprons and terminals and ancillary buildings at the airports and civil enclaves;(aa) establish airports, or assist in the establishment of private airports, by rendering such technical, financial or other assistance which the Central Government may consider necessary for such purpose;(b) plan, procure, instal and maintain navigational aids, communication equipment, beacons and ground aids at the airports and at such locations as may be considered necessary for safe navigation and operation of aircrafts;(c) provide air safety services and search and rescue, facilities in co-ordination with other agencies;(d) establish schools or institutions or centres for the training of its officers and employees in regard to any matter connected with the purposes of this ActETC.