This section applies only to a public service company that is an investor–owned gas company or investor–owned electric company. In a base rate proceeding to set just and reasonable rates under this title, each public service company shall demonstrate to the Commission the reasonableness of the use of internal labor in comparison to contractual labor. To demonstrate reasonableness of the use of labor as required under subsection (b) of this section, a public service company shall provide to the Commission, at a minimum: a comparison of the costs of internal labor and contractual labor; a demonstration of the reasonableness of the decision to use contractual labor; a justification for the use of contractual labor when used instead of internal labor, including a cost–based rationale; and any other information that the Commission requires.