The correct answer is D) red and black bands. Buoys that mark isolated dangers, such as a wreck or rock, are painted with alternating red and black bands to clearly indicate the presence of a hazard that should be avoided. This is in accordance with the U.S. Aids to Navigation System, which is the standardized system used to mark waterways and hazards. The other answer choices are incorrect because green and white bands are used for safe water marks, red and white stripes are used for preferred channel markers, and green and black bands are not a standard color scheme for any type of navigational buoy.