(a) If the authorizing municipality adopts the tax under Section 504.251, a tax is imposed on the receipts from the sale at retail of taxable items within the municipality at the rate approved by the voters.
(b) The rate of the tax imposed under Subsection (a) may be any rate that is an increment of one-eighth of one percent, that the authorizing municipality determines is appropriate, and that would not result in a combined rate that exceeds the maximum combined rate prescribed by Section 504.254(a).