选D,not wanting和前面的realizing并列,都是分词引导的状语从句.C不对是因为不定式做状语一般表目的这里显然不是表目的.
动词不定式和分词作状语的区别：
1)分词作状语一般表示伴随,而不定式常常表示目的.
They stood by the roadside talking about the plan．他们站在路边谈论着这个计划.(伴随)
They stood by the roadside to talk about the plan．他们站在路边为的是谈论这个计划.(目的)
2)分词作状语放在句子开头,除表示原因之外有时表示时间或条件.动词不定式作状语时,除了表示目的以外,还表示结果或原因.
Reading attentively,he forgot the time for lunch．由于在专心读书,他忘了吃午饭的时间.(原因)
Reading carefully,he found something he had not known before．他仔细读书时,发现了一些从前不知道的东西.(时间)
Reading carefully,you'll learn something new．只要你仔细阅读,你会学到一些新的东西.(条件)
His family was too poor to support him．他的家庭太穷,不能维持他的生活.(结果)
The boy is not tall enough to reach the book shelf．这男孩个子不够高,手伸不到书架.(结果)
We are glad to hear the news．我们很高兴听到这消息.(原因)