Which invention is attributed to the Wright Brothers?

The invention attributed to the Wright Brothers is the powered airplane. They achieved this milestone on December 17, 1903, when Orville and Wilbur Wright successfully flew the first heavier-than-air powered aircraft, known as the Wright Flyer. This aircraft was significant because it was the first to demonstrate controlled, sustained flight with a pilot aboard, which was a pivotal moment in aviation history.

While the glider is related to their early experimentation in flight, and the brothers did create gliders before developing the powered aircraft, it was their innovation in adding an engine and propellers that led to the first powered flight. The helicopter and balloon do not relate directly to the Wright Brothers’ contributions, as these are separate forms of air travel developed by other inventors. Thus, the correct answer highlights their groundbreaking achievement in creating the first successful powered airplane.