请教 prep 数学一道

独孤求败

set s consists of 5 consecutive integers, set t consists of 7 consecutive integers, is the median of the numbers in set s equal to the median of the numbers in set t?

1.the median of the numbers in set s is 0

2.the sum of the numbers in set s is equal to the sum of the numbers in set t

我觉得b就足够了，怎么答案是c呢，高手帮帮忙了