Ten new television shows appeared during the month of September. Five of the shows were sitcoms, three were hour-long dramas, and two were news-magazine shows. By January, only seven of these new shows were still on the air. Five of the shows that remained were sitcoms.
Which statement must be true according to the given information?
I. Only one of the news-magazine shows remained on the air.
II. Only one of the hour-long dramas remained on the air.
III. At least one of the shows that was cancelled was an hour-long drama.
IV. Television viewers prefer sitcoms over hour-long dramas.

Question: 以下哪项是正确的？
Options:
A. 仅 IV, B. 非 IV, C. 仅 III, D. 以上各项均不成立, E. 非 I
Answer: B
C
E
True statement: III