Which of the following types of feathers is used for flight in birds?

The type of feather that is used for flight in birds is called a "quill" feather. Quill feathers are large, strong, and stiff feathers located on the wings and tail of birds. They are responsible for providing lift and control during flight. Quill feathers have a central shaft or "quill" that is surrounded by many small branches or "barbs". These barbs are interlocked with each other, forming a flat surface that helps birds to fly. Additionally, quill feathers are coated with a special oil that makes them water-resistant and helps to keep birds dry while they are in flight.