What main point does Adam Martin make about video games?

A、 People are learning how to avoid becoming addicted to them.
B、 They enable people to learn without being aware of it happening.
C、 They satisfy a need for people to compete with each other.
D、 People learn a narrow range of skills but they are still useful.

【正确答案】 B

【答案解析】解析：The fifth paragraph says 'Computer games teach and people don't even notice they're being taught.' Distraction A: Although he mentions 'addictiveness', there is no suggestion of people trying to become less addicted; C: Although he talks about 'a set of challenges', he does not say anything about people competing with each other; D: The writer suggests the possibility of learning being narrow but Martin does not.