What is black ice?

• Oil present on the road
• A cube of black-colored ice on the curb
• A thin layer of ice covers the road
  Explanation:

  "Sections of roads in shaded areas or on bridges and overpasses freeze first. It is important to look ahead, slow down, and anticipate ice. If the road ahead looks like black and shiny asphalt, be suspicious. It may be covered by a thin layer of ice known as black ice."
• None of these