In the 1890s the first commercial automobiles began to arrive in Sacramento. By 1905, twenty-seven automobiles were registered in Sacramento County. By 1910, seven hundred more were registered, and by July 1911, in what can only be called "Auto Frenzy," Sacramentans were buying seventy-five autos per day. Automobiles alone could not make a significant difference. A network of paved roads was essential. Three bridges had to cross the American River between Sacramento and Fair Oaks. Perhaps the best symbol of this growing network would be the completion of the Yolo Causeway in 1916.
What is the MAIN méthod of organization of ideas in this passage?a. spatialb. chronologicalc. cause and effectd. least to most important