a. Whenever any municipality, pursuant to the authority granted in section 7 of this act, shall amend its charter to include an alternative permitted under its plan of government and included in Group B. of subsection b. of section 7 of this act, the terms of all council members, and directly elected mayor if affected, currently serving in the municipality on the date of the election at which the amendment was adopted, and of all affected officers elected at that election, shall terminate on June 30, or December 31, as appropriate to the election provisions of the amended charter, next following the date of the first election of officers under the amended charter. The nomination and election of those municipal officers as are required shall be conducted in accordance with the provisions of the amended charter and appropriate law for the election to be held on the second Tuesday in May next following the date of adoption, or on the first Tuesday after the first Monday in November next following the date of adoption. If the amendment adopted to the charter shall provide for the division of the municipality into wards, or by its terms require an increase or decrease in the number of wards into which the municipality is divided, the ward boundaries required by the amended charter shall be fixed and determined pursuant to law within 90 days of the date of adoption. If the municipality shall at the same time amend its charter to include an alternative permitted under its plan of government and included in Group A., Group C., Group D. or Group E. of subsection b. of section 7 of this act, the transitional provisions of this section shall apply and the provisions of all amendments shall take effect for the election to be held pursuant to this section.