The correct answer is C. DRM.
The DRM (Diretor Regional de Manutenção) is the Regional Maintenance Director of CPTM (Companhia Paulista de Trens Metropolitanos). The DRM is responsible for the maintenance and operation of the suburban train network in São Paulo, Brazil. The DRM signs the Suburban Working time table, which is a document that outlines the schedule of trains on the suburban network.
The DOM (Diretor de Operações Metropolitanas) is the Director of Metropolitan Operations of CPTM. The DOM is responsible for the planning and coordination of all operations on the suburban train network. The DOM does not sign the Suburban Working time table.
The AOM (Assistente de Operações Metropolitanas) is the Assistant to the Director of Metropolitan Operations of CPTM. The AOM provides support to the DOM in the planning and coordination of operations on the suburban train network. The AOM does not sign the Suburban Working time table.
None of the other options are correct.