Solution:Under the Industrial Disputes Act, 1947, various authorities have been established to address industrial disputes:
Board of Conciliation: Section 5 outlines the establishment of a Board of Conciliation to mediate and promote the settlement of industrial disputes.
Court of Inquiry: According to Section 6, a Court of Inquiry can be set up to investigate any matter of public importance related to an industrial dispute.
Industrial Tribunal: Detailed in Section 7, the Industrial Tribunal is established to adjudicate on industrial disputes relating to specific matters.
National Tribunals: Section 7B introduces National Tribunals to handle disputes of national importance or if they involve questions of natural justice.
Voluntary Arbitration: This is a method by which industrial disputes are settled amicably through arbitrators appointed by parties mutually, as defined in Section 10A. Ascending order of the given question is (d), (c), (a), (e), (b).