Sparva, unlike Treland' s other provinces, requires automobile insurers to pay for any medical treatment sought by someone who has been involved in an accident; in the other provinces, insurers pay for nonemergency treatment only if they preapprove the treatment. Clearly, Sparva' s less restrictive policy must be the explanation for the fact that altogether insurers there pay for far more treatments after accidents than insurers in other provinces, even though Sparva does not have the largest population. Which of the following, if true, most strengthens the argument? ['Different insurance companies have different standards for determining what constitutes emergency treatment.', 'There are fewer traffic accidents annually in Sparva than in any of the provinces of comparable or greater population.', 'The cost of medical care in Sparva is higher than the national average.', 'Fewer insurance companies operate in Sparva than in any other province.']