Question

________ Mary is going to marry？

1. A.
   Who do you think
2. B.
   Do you think who
3. C.
   Who you think
4. D.
   Does who you think

Answer 1

A
解析：
do you think出现在特殊疑问句中作插入语，前后不用逗号分开，问句后面要用陈述语序。