she went up to the shop assistant ----(who ,when ,where ,how)sold the beef to her

问题描述:

she went up to the shop assistant ----(who ,when ,where ,how)sold the beef to her
为什么?

who
他走向那个卖给他牛肉的营业员
这里shop assistant是人,所以先行词用who引导,是shop assistant卖给他牛肉的