Look at this series: 17, ____, 28, 39, 39
What number should fill the blank?
I. 50
II. 39
III. 25
IV. 17
Question: 以下哪项是正确的？
Options:
A. 以上各项均不成立
B. 只有 IV
C. IV 或 III
D. 仅 I
E. 仅 III
Answer: B
C
True statement: IV