Municipal option for temporary lower interest rate on certain delinquent property taxes and utility rates, charges and assessments.

(2) At the conclusion of the ninety days during which the delinquent portion of any tax, rate, charge or assessment described in subsection (a) of this section shall be subject to interest at a rate of three per cent per annum, pursuant to said subsection, such delinquent portion, if any, shall be subject to interest and penalties as otherwise provided by law. (b) The provisions of subsection (a) of this section shall not apply in the case of any tax, rate, charge or assessment described in said subsection that is subject to interest and penalties at less than three per cent per annum.