6. If any question arises whether any duty is military, naval or air-force duty within the meaning of this Act, the decision of the Government thereon shall be conclusive.If any question arises whether any person is compelled as aforesaid to reside within the limits of a municipality or is bound as aforesaid to keep any horse, the decision thereon of such authority as the Government may, from time to time, appoint in this behalf shall be conclusive.