Muscular strength is a limited resource, and athletic techniques help to use this resource efficiently. Since top athletes do not differ greatly from each other in muscular strength, it follows that a requirement for an athlete to become a champion is a superior mastery of athletic techniques. Which one of the following most accurately expresses the conclusion of the argument? ['The differences in muscular strength between top athletes are not great.', 'No athlete can become a champion without a superior mastery of athletic techniques.', 'Only champion athletes have a superior mastery of athletic techniques.', 'Superior muscular strength is a requirement for an athlete to become a champion.']