(a) Decision on petition. Upon receipt of the petition the commission shall within thirty (30) days determine whether to deny the petition or to initiate regulation-making proceedings in accordance with law.

(b) Procedure on denial. If the commission denies the petition, the commission shall give the petitioner notice in writing, stating the reasons for the denial based upon the data, facts, and arguments submitted with the petition by the petitioner and upon such additional data, facts and arguments as the commission shall deem appropriate.