Most of the developing countries are faced with lots of troubles , the financial problem is not the worst .
A. which
B. with which
C. that
D. of which
网友回答
A. which
B. with which
C. that
(答案→)D. of which
解析：考查非限制性定语从句。the financial problem和troubles是所属关系，应该用介词of；本句是非限制性定语从句。故选D。