Which feature best defines a Sandbar?

• A. A cliff formed by erosion.
• B. A ridge of sand deposited by longshore drift that runs parallel to the shore.
• C. A coastal dune behind a barrier.
• D. A coral reef.

Answer: (B)

Longshore drift moving sediment along the coast creates a low, elongated ridge of sand that sits in the surf zone and runs roughly parallel to the shoreline. This parallel sand ridge is the hallmark of a sandbar, forming where wave energy slows and deposits accumulate in the nearshore, often acting as a barrier between the open sea and the more protected water behind it. The other options reflect different coastal features: a cliff is sculpted by erosion of rock, dunes are wind-formed sand accumulations inland from the beach, and a coral reef is a biological structure built by corals in warm shallow seas.