13. Pursuant to a law ordering the fixing of “just and reasonable standards, classifications, regulations, practices, or services to be furnished, observed and imposed by operators of public utility vehicles,” the Land Transportation Franchise and Regulatory Board (LTFRB) promulgated and published a regulation that “no car beyond six years shall be operated as a taxi.” Taxi operators assailed the validity of the regulation contending that procedural due process was violated because position papers were not asked of them and no notice was given to them prior to the issuance of the regulation. Were the taxi operators denied procedural due process? Explain briefly. (5 points)