A revenue bond is distinguished from a general obligation bond in that revenue bonds have which of the following characteristics?

a. They are issued by counties, special districts, cities, towns, and state-controlled authorities, whereas general obligation bonds are issued only by the states themselves.

b. They are typically secured by limited taxing power, whereas general obligation bonds are secured by unlimited taxing power.

c. They are issued to finance specific projects and are secured by the revenues of the project being financed.

d. They have first claim to any revenue increase of the issuing tax authority.