Company X maintains a defined benefit plan and a 401(k) plan for its employees and for the employees of a number of subsidiaries. Two other subsidiaries, Y and Z, (which are both subs of X) maintain their own plans and do not participate in X's plans. Company H is the parent organization and is merely a holding company with no employees. Section 10.06 permits the parent of a parent-sub controlled group to elect to file all of the plans under the remedial amendment period cycle determined by the last digit of the parent's EIN. Can X, Y and Z treat X as the parent for this purpose and have X make this election?