Statistics show that train accidents in a country mostly occur in the southern region, so it is safer to travel by train in the northern region. Which of the following can best refute the above argument? ['Slower train speeds in the north of the country.', 'There are many more train lines in the south of the country than in the north.', 'Many lines in the south of the country already use EMUs.', 'Most of the northern part of the country is mountainous and is more suitable for car driving.']