●  The main objective of the 1929 act was to make provisions for establishment of courts of Inquiry and Boards of Conciliation with a view to investigate and settle trade disputes.

●  The act prohibited strikes or lock-outs without notice in public utility services

●  It made any strike or lock-out illegal which had any object other than the furtherance of a trade dispute within the trade or industry.

●  It provided for the system of the tribunals and the ban on strikes. Hence statement d is correct.