--How's Joy's skirt?--Her skirt is more beautiful than _____

--How's Joy's skirt?--Her skirt is more beautiful than _____.
--How's Joy's skirt?
--Her skirt is more beautiful than _____.
A.her sister's and Kate B.her sister and Kate
C.her sister and Kate's D.her sister's and Kate's
选哪一个 理由是.
但是more不是两者之间吗 her sister's and Kate's and her own 不是三人之间的比较吗 那应该用must