Asandbar that completely crosses a bay, sealing it off from the open ocean, is a tombolo coastal barrier sea stack none of these

The right answer is none of these

none of these words adapts to this definition:

A pile of the sea is a pillar of rock detached by the action of the waves of a bank of cliffs.

Tombolo looks like an island attached to the mainland by a narrow terrain.

Coastal barriers are unique landforms that protect a variety of aquatic habitats by establishing a line of defense.

b. lithosphere, asthenosphere, mesosphere   is the answer most likely