Answer:
Parabolic dunes
Step-by-step explanation:
A parabolic dune is a U-shaped mound of sand. The tips point upwind because they are anchored by vegetation.
A is wrong. The tips of a barchan dune point downwind
C is wrong. A longitudinal dune is parallel to the prevailing wind.
D is wrong. The ridge of a transverse dune is perpendicular to the prevailing wind.