Between the lates 1930s and 1940s, the Brown Calendar Company produced a series of cale...

Between the lates 1930s and 1940s, the Brown Calendar Company produced a series of calendars featuring trains of the California Railroad. Up to three hundred thousand of there, featuring large, colorful scenes of trains at work, were published every year to hang in depots and shippers officers along the lines of the famous company. The scenes, mostly painted by one artist, Graham Teller, are now valuable collectibles. According to the text above choose the right alternative: What is the subject of this passage?