The most credible and reliable support for the argument in favor of lowering the age to get a driver's license to 14 years of age would be:
A national news broadcast reports that in South Dakota, teenagers as young as 14 years old can receive their restricted driver’s permits.
This evidence is credible because it provides a concrete example of another state's policy regarding driver's licenses for 14-year-olds, suggesting that it is possible and accepted in some places. It presents information from a reputable source that could support the argument more effectively than personal anecdotes or isolated observations.