I don't like such a person （ ）talks much but does little.

选D
如果是I don't like a person （ ）talks much but does little.没了such,就who和that都行
但这里
I don't like such a person （ ）talks much but does little.
such……that
so……that是定语从句的又一固定用法

that与who的用法区别

(1) 两者均可指人，有时可互换：

All that [who] heard him were delighted. 所有听了他讲话的人都很高兴。

Have you met anybody that [who] has been to Paris? 你遇见过到过巴黎的人吗?

He is the only one among us that [who] knows Russian. 他是我们中间惟一懂俄语的人。

(2) 但是在下列情况，通常要用 that：

①当先行词是一个既指人又指物的并列词组时：

I made a speech on the men and things that I had seen abroad. 我就我在国外所见到的人和事作了报告。

②当先行词是who时(为避免重复)：

Who that has sympathy can laugh on that occasion? 有同情心的人谁会在那个时候发笑呢?③当关系代词在定语从句中作表语时(可省略)：

Tom is not the boy (that) he was. 汤姆这孩子已不是以前那个样子了。

定语从句中只能使用that的情况

1.当先行词为anything，everything，nothing等不定代词时，只能使用“that”。例：Is there anything that I can do for you?(我能给你做点什么吗？)

2.当先行词为a