Read the article and select the best answer. Article: The robot moved into the fighting ring with confidence.Then it turned around quickly and knocked itself over. The team of Scouts that built the 8-inch -tall machine immediately realized one arm was too long.They would have to work fast---practice time was over , and the real robot matches were about to begin . "We tried to fix it , but by that time , the other teams had more advanced technology ," says Eagle Scout Matthew Patchen , 16. "They were a couple of steps ahead of us ." In the end , Matthew's team didn't win the robot competition . But they had a great time working on their Robotics merit badges at the 2011 Advance Camp in Antioch , Calif . Advance Camp is held the last Saturday in September at the Contra Costa County Fairgrounds in Antioch, Calif.Nearly 1,500 Scouts attended in 2011 and worked on different merit badges .Scouts choose from more than 50 merit -badge classes taught by counselors .They can earn merit badges from Fingerprinting to Nuclear Science to Swimming .Robotics is the most popular class . First , one of the counselors talked to Matthew and the other Scouts in his Robotic class about the many different uses for robots . "I learned how advanced it really is ," Matthew says . "Robots are used in medicine and industry ." After the talk , the Scouts were divided into five-person teams . Each team was required to build a basic robot . The next step was programming the tiny computer in the robot so it would make the right moves once it was in the ring . "We programmed our robot so its arm was moving all the time ," Matthew says . "That way , it would knock the other robot over." . That's when they discovered the arm on their robot was too long . As a result , their robot knocked itself over before it could fight with any other robots . "It was a learning experience ," Matthew says . "You have to think ahead." Question: The author writes this text mainly to _ . Options: A: explain what Scouts do B: introduce an interesting camp C: advertise a robot competition D: encourage Scouts to learn technology
The answer to this question is:
B