In the Hartshorn Building, most but not all of the third-floor offices are larger than any office on the second floor. The fourth-floor offices are all larger than any office on the second floor. However, all the second-floor offices are larger than any office on the first floor. If the statements above are true, which one of the following must also be true? ['Some first-floor offices are as large as the smallest fourth-floor offices.', 'Some fourth-floor offices are not as large as the largest third-floor offices.', 'Some first-floor offices are as large as the smallest third-floor offices.', 'Some third-floor offices are not as large as the smallest fourth-floor offices.']