With ( ) does she live?She lives with her cousin in a small house.

B whom
With ( ) does she live?She lives with her cousin in a small house.
她和谁一起住?她和表（妹）住在一个小房子里.
因为with 后面是要宾格,就好像是　with her,him,me 一样,who的宾格是whom,所以填它