China will soon put its first domestically developed electric aircraft into mass production, and designers expect a huge market at home and abroad. "The RX1E is scheduled to receive its airworthiness(,,)certificate from the Civil Aviation Administration of China before the end of this year, with production expected to start next year," Yang Fengtian, an academic at the Chinese Academy of Engineering told China Daily on Thursday. "This will be the first electric aircraft to be certified by our civil aviation authority. The success of the plane means China has become a technology leader in this filed," he added. An electric aircraft runs on electric motors, with electricity coming from fuel cells, solar cells, ultracapacitors, power beaming or batteries. Most of today's electric aircraft are experimental demonstration models. The first manned, electrically powered flight was made in 1973. "We plan to reach an annual production of 100 such aircraft within three years, and the construction of a manufacturing plant that can make 100 RX1Es each year has begun in Shenyang," Yang said, adding that the plane, together with a set of batteries, will sell for nearly 1 million yuan ($163,000). The convenience of use, easy maintenance, low operating costs, high safety levels and eco-friendliness will bring the RX1E many buyers to serve a wide range of purposes, such as police patrols, flight training, entertainment and mapping surveys, he added. Yang said he expects that the Chinese market will need at least 1,000 RX1Es to meet the demand from general aviation businesses. With a maximum takeoff weight of 480 kg and a cruise speed of up to 160 kilometers per hour, the RX1E can fly 90 minutes based on a full charging of its batteries. It is able to carry loads for 230 km and fly at an altitude of nearly 3,000 meters. Yang said, "In addition to the domestic market, _ ." Which option is not the advantage of RX1E according to the passage?
RX1E can utilize different energy source to power the engine. RX1E has a big size, thus it can serve multiple purposes. RX1E does not cause as much harm to the environment. RX1E can be operated and maintained easily at an acceptable price.