_____as the most excellent student in her university,as most classmates……

_____as the most excellent student in her university,as most classmates……

选C。
选A语法上就不正确了。你先划掉as the most...as...expected这一部分别看，因为它是从句起修饰作用，我们先看主句。划掉这部分后只剩下_____ made her parents very happy. 这时你怎么选？ Amy was chosen本身就是一个完整的句子，这以 made her parents very happy相冲突，所以不能选。 而C则可以以一个被动的动名词词组来做主语的成分。

A 是主谓结构
这整个句子的结构是：。。。让她的父母很高兴。所以这里肯定是一个谓语。什么让他的父母很高兴。Amy's being chosen made her parents very happy.
而不是：Amy was chosen made her parents very happy.那这里就有两个谓语了。

C 因为句子的主语就是Amy's being chosen, 谓语是made
如果选A 那么made 的主语找不到了。Amy was chosen as the most ...一个完整句子不能做后面made 的主语。
as most classmates had expected做题时，可以视同为插入成分，先不用管它。