Section 9F. A county, except Worcester county, by vote of the county commissioners; a city having a Plan D or Plan E charter by majority vote of its city council; in any other city by vote of its city council, approved by the mayor; a district, except as herein provided, by vote of the registered voters of the district at a district meeting; a regional school district by vote of the regional district school committee; a veterans' service district by vote of the district board; a health district established under section twenty-seven A of chapter one hundred and eleven by vote of the joint committee, shall provide that an employee receiving a pension or annuity allowance having retired from the governmental unit may be insured for such greater amount of group life insurance and for such greater amount of group accidental death and dismemberment insurance as determined by the governmental unit, in lieu of the one thousand dollars of group life insurance as provided in section nine. A town shall provide such insurance coverage if approved by vote of the board of selectmen, or by a majority of the votes cast if in the affirmative in answer to the following question which shall be printed on the official ballot:
''Shall the town provide (X) thousand dollars of group life insurance and (X) thousand dollars of accidental death and dismemberment insurance for a retired employee in lieu of one thousand dollars of group life insurance?''
Acceptance of this section as aforesaid by a governmental unit having accepted section eleven E shall hereby authorize the commission to provide such greater amount of group life insurance and of such greater amount of group accidental death and dismemberment insurance, in lieu of one thousand dollars of group life insurance, to retired teachers insured under section twelve of chapter thirty-two A.