Answer:
Not all professional football players who played the sport as youths ignored the advice of coaches.
Step-by-step explanation:
According to the second sentence of the passage, a necessary condition for being a successful professional football player is not ignoring the advice of coaches. So all of the successful professional football players mentioned in the passage's first sentence, including those who played the sport as youths, do not ignore the advice of coaches. That’ s what the correct answer states.