应该用who。
在限制性定语从句中，当先行词指人时，关系词可用who(m)或that，二者常可互换。但在下列情况中,用who(m)，而不用that：
（1）当先行词是one,ones,any,few,anyone,anybody,someone,somebody,everyone,
everybody等词时。如：
Is there anyone who can answer this question?
He was among the few who managed to live through the enemy prison camp.
注：在非正式文体中可以说：You’re the one that knows where to go.
（2）当先行词是he，they，those，people，person等词时。如：
He who wants to catch fish just not mind getting wet.
Those who are against the proposal put up your hands.
注：在固定结构的谚语或习语中，可用he that….如：
He that promises too much means nothing.
（3） 当先行词有较长的后置定语修饰时。如：
Do you know the writer in blue with thick glasses who is speaking at the meeting?
（4）在分隔式定语从句中，若先行词指人，为了明确修饰关系，应当用who(m)。如：
A new master will came tomorrow who will teach you German.
There’s only onestudent in the school who/whom I wanted to see.
I was the only person in my office who was invited.
（5） 两个定语从句同时修饰一个指人的先行词,第二个定语从句常用who(m)来引导，如：
She is the only girl I know who can play the guitar.
用that 而不用who (whom)的情形
(1) 当先行词前面有形容词的最高级或序数词修饰时，引导词只能用that。如：
The tallest player that plays football for our team is from Shandong.
在为我们队踢足球的最高哪个运动员来自山东。
(2) 当先行词前面有only, some, any, no, every, little, few, much, all, very形容词修饰时，引导词只能用that。如：
He is the only student that said “no” to the teacher.
他是唯一的一个对老师说“不”的学生。
(3) 当主句是以who开头的特殊疑问句时，引导词只能用that。如：
Who is woman that you talked with just now?
刚才跟你谈话的那位妇女是谁？
(4) the same as 与 the same that
the same as所引导定语从句的内容与先行词同类而不同物；the same that表示所引导的从句内容与先行词同类同物，即：同一事物。如：
She is wearing the same coat that I lost a few days ago.
她正穿着我几天前所丢失的上衣。(暗含：她偷了我的上衣)
She is wearing the same coat as I lost a few days ago.
她正穿着跟我几天前所丢失的上衣同样的上衣。(暗含：她所穿的上衣不是我所丢失的那一件)