One of the greatest advantages of robots is that they can work insituations that are dangerous or harmful for human workers. For example,the continuous smell of paint has a harmful effect on painters, but itdoesn't "bother" a robot. Robots can work in nuclear power plants and inundersea research stations that might be dangerous for humans. Already,robots are working in the plastics industry and in chemical and industrialequipment industries. One of the most common uses of robots is still inautomobile factories. They can do the heavy, unpleasant, or dangerouswork. These kinds of industrial robots are not usually "mobile". Thework they need to do is brought to them, like cars on an assembly line,for example. The robot industry is a big business. By the middle of the 1990s,Japan led the world in robot production with more than 71,000 industrialrobots at work. Both the United States and Japan, as well as othercountries, continue to develop more advanced robots. Robots can now bemade to perform more complex jobs. Robots can make decisions whilethey are working and learn from their mistakes. Robots can now see withTV camera "eyes." They can easily hear and can even speak using a voicemade by a computer. But it is difficult to make a robot "understand."Thinking and understanding are very human qualities. The robots of thefuture will probably be very complex. They will be able to perform manyhumanlike tasks. Robots and other technology will make the future a veryinteresting place! We can infer from the passage that by the middle of the 1990s______________.

A. some countries had used robots in industrial production

B. Japan and the USA were the only countries to use robots

C. only Japan had used robots in production

D. Japan led the world in production thanks to robots