Which of the following, if true, most logically completes the argument? A. far fewer people used the subway system when it was built 25 years ago than use it today B. seven-car trains cannot carry enough passengers to eliminate the overcrowding C. subway officials have not seriously considered any means of eliminating overcrowding other than using longer trains D. nine-car trains cannot be accommodated at the existing platforms E. the current overcrowding, although frustrating to passengers, does not violate any subway safety laws