．What sets human beings apart from animals is not the pursuit of happiness, but the pursuit of meaning, is unique to humans.
A. that
B. what
C. which
D. as
网友回答
A. that
B. what
(答案→)C. which
D. as
解析：C 考察定语从句。本句是一个非限制性定语从句，which指代整个一句话的内容。As虽然也可以引导非限制性定语从句，但一般是指正如，且常用与被动语态中。故C正确。