Whenever the trustees are elected at one regular school election under the circumstances described in 20-3-302(2)(a), the members who are elected shall draw by lot to determine their terms of office. The terms of office by trustee position must be: (1) three for 3 years, two for 2 years, and two for 1 year in a first-class elementary district; (2) two for 3 years, two for 2 years, and one for 1 year in second-class elementary districts and third-class elementary districts having five trustee positions; or (3) one for 3 years, one for 2 years, and one for 1 year in a third-class elementary district having three trustee positions.