Which of the following is a characteristic of General Obligation bonds?

General Obligation bonds are distinct in that they typically require voter approval before issuance. This is because they are backed by the full faith and credit of the issuing governmental entity, which means that the government is committed to using its tax revenue to repay bondholders. The need for voter approval reflects the significant impact such bonds can have on public finances, as it often involves increasing taxes or reallocating government resources.

The other characteristics mentioned in the choices do not apply to General Obligation bonds in the same definitive manner. For example, while they may not be directly secured by specific revenue sources like revenue bonds, they are ultimately backed by the issuer's taxing power. Additionally, the interest rates on General Obligation bonds tend to be lower compared to other bond types, as they carry less risk due to the backing of tax revenue and voter approval, attracting investors seeking a safer option. Thus, the requirement for voter approval is a fundamental characteristic that emphasizes the bond’s alignment with public accountability and governance.