Final answer:
A 'one arrow, U shape' dune likely refers to a barchan dune, which is crescent-shaped with horns pointing downwind. The correct option is A.
Step-by-step explanation:
The type of dune described as having a 'one arrow, U shape' is most likely the barchan dune. Barchan dunes are crescent-shaped dunes that have tips, or 'horns', pointing downwind, resembling a 'U' or a bow shape.
They are formed by winds that predominantly blow from one direction and are common in areas with a limited supply of sand and a relatively hard, flat surface beneath.
The windward side of the barchan dune is gentle and slopes upwards, while the leeward side is steep and is the site of sand being deposited, often creating cross-bedding in the sand layers when preserved in the rock record.
The other options, such as Seif dunes, are more elongated and aligned with prevailing winds, linear dunes are straight or slightly sinuous sand ridges typically formed in regions of bidirectional winds, and dome dunes are circular mounds of sand with no slip face that are more rare and form in areas with multi-directional wind regimes.
The correct option is A.