Upon the adoption of an ordinance of intention, or the presentation of a petition, as provided in Article 2 (commencing with Section 2931), the legislative body of the municipal corporation shall, by ordinance, order the holding of a special election for the purpose of submitting to the qualified electors of the municipal corporation the propositions set forth in the ordinance of intention or in the petition, as the case may be, or the legislative body shall, by ordinance, order the submission of the propositions at a general municipal election.