37. This English course is very helpful for me. The course concentrates on developing communicative skills. (that)
A. This English course which concentrates on developing communicative skills is very helpful for me.
B. This English course that concentrates on developing communicative skills is very helpful for me.
C. This English course who concentrates on developing communicative skills is very helpful for me.
D. This English course, that concentrates on developing communicative skills is very helpful for me.