Please answer the following question: Read the following article and select the best answer. Article: The Segway Human Transporter was invented by Dean Kamen.It is a two-wheeled vehicle designed for a single rider standing upright over its single axle and navigate using a set of handlebars resembling those on a bicycle.Electrically powered, it could travel over 15 miles on a single charge and reach speeds up to twelve miles per hour.Its speed and direction can be controlled by riders' changing their weights. A college dropout and self-taught engineer, Kamen already held over 100 patents for his inventions when he developed the one he hoped would revolutionize short-distance travel.While still in college, Kamen started developing the medical devices that made his name.Later, he changed focus to the challenges faced by wheelchair users.His robotic wheelchair known as IBOT could climb stairs.This robot ended up paving the way for the Segway. Before showing his most recent invention, Kamen had kept it a top secret for months.When it turned out to be little more than a motor scooter, many publicly expressed their disappointment.On closer examination, however, even his critics had to admit that the vehicle was an engineering achievement.It answered the prayers of anyone who is worn out when walking downtown.Not everyone welcomed the Segway's arrival, though.Some complained it was too expensive, while others said it would further weaken the average American ' s fitness.A Japanese inventor even accused Kamen of stealing the idea for the Segway from him. Despite the controversy, the U.S.postal service began using Kamen's invention a month after its appearance, and a factory was built with plans to produce about 40,000 Segways every month.The argument is still on whether the Segway will be remembered as the greatest invention since the light bulb, or just another forgettable electronic device.Anyway, trips to the local supermarket will never be the same again. Question: Which statement best describes the critics' reaction to the Segway? - Nothing but an electrical device. - A disappointing engineering mistake. - An expensive and disappointing invention. - Disappointing, but still a successful device.
Answer:
Disappointing, but still a successful device.