(a)      The Commissioner may conduct an investigation under Subtitle 2 of this title, on the Commissioner's own initiative or may require a written complaint.

      (b)      The Commissioner may conduct an investigation under Subtitle 4 of this title, on the Commissioner's own initiative or on receipt of a written complaint.

      (c)      The Commissioner may conduct an investigation to determine whether Subtitle 5 of this title has been violated on receipt of a written complaint of an employee.

      (d)      (1)      The Commissioner may investigate whether § 3-701 of this title has been violated on receipt of a written complaint of an applicant for employment.

            (2)      The Commissioner may investigate whether § 3-702 of this title has been violated on receipt of a written complaint of an applicant for employment or an employee.