Birds fly with the help ofA)PatagiumB)WingC)FeatherD)Limbs

The correct answer is B) Wing.

Explanation:
Wings are the primary structures that allow birds to fly. They are specially adapted with a combination of bones, muscles, and feathers designed for flight. The shape and movement of the wings generate lift, which counteracts gravity, allowing the bird to stay airborne.

Other options:

A) Patagium: This is the membrane of skin present in some animals (like bats) and also found in birds. In birds, it helps in the mechanics of flight but is not solely responsible for flying.
C) Feather: Feathers cover the wings and play a crucial role in aerodynamics, insulation, and maneuvering. While important, they are not the direct organ of flight.
D) Limbs: In birds, the forelimbs are modified into wings. However, "limbs" as a term does not specifically refer to the structures enabling flight.
Thus, the wings are the key anatomical feature that allows birds to fly.