(a) Upon receipt of the petition in the Regional Office, it is filed, docketed, and assigned to a member of the staff, usually a field examiner, for investigation. The field examiner conducts an investigation to ascertain:

(1) Whether the employer's operations affect commerce within the meaning of the Act,

(2) Whether there is in effect an agreement requiring as a condition of employment membership in a labor organization,

(3) Whether the petitioner has been authorized by at least 30 percent of the employees to file such a petition, and

(4) Whether an election would effectuate the policies of the Act by providing for a free expression of choice by the employees.

(b) The petitioner may on its own initiative request the withdrawal of the petition if the investigation discloses that an election is inappropriate, because, among other possible reasons, the petitioner's card-showing is insufficient to meet the 30-percent statutory requirement referred to in subsection (a) of this section.

(c) For the same or similar reasons the Regional Director may request the petitioner to withdraw its petition. If the petitioner, despite the Regional Director's recommendation, refuses to withdraw the petition, the Regional Director then dismisses the petition, stating the grounds for his dismissal and informing the petitioner of the right of appeal to the Board in Washington, DC. The petitioner may within 14 days appeal from the Regional Director's dismissal by filing such request with the Board in Washington, DC. The request shall contain a complete statement setting forth the facts and reasons upon which the request is made. After a full review of the file with the assistance of its staff, the Board may sustain the dismissal, stating the grounds for its affirmance, or may direct the Regional Director to take further action.