Each contractor and subcontractor subject to this subtitle shall pay each employee not less than the prevailing wage rate required under this subtitle: unconditionally; without subsequent rebate; and except as provided in subsection (b) of this section, without deductions for: food; sleeping accommodations; transportation; use of small tools; or any other thing of any kind. A contractor or subcontractor may make deductions that are: required by law; required or allowed by a collective bargaining agreement between a bona fide labor organization and the contractor or subcontractor; or contained in a written agreement between an employee and an employer undertaken at the beginning of employment, if the agreement: concerns food, sleeping accommodations, or other similar items; is submitted by the employer to the public body awarding the public work contract; and is approved by the public body as fair and reasonable.