There are secret gangs of young people skilled in martial arts , who patrol the streets at night . They used to use their powers for good by , like , fighing crime or something , but now all the gangs are little more than criminals themselves . Except for one : the Purifiers .

Question: Why are the young people skilled in martial arts ?
Answer: Because they patrol the streets at night .None of the above choices .Because they used their powers for good .Because they are in secret gangs .