Crusoe’s dog became ill and died,         made him very lonely.

1. A.
   this
2. B.
   that
3. C.
   which
4. D.
   as

Crusoe's dog became ill and died, ____ made him very lonely.

A. this                        B. that                        C. which                            D. as 

Choose the best answer which can complete the sentence.

Crusoe's dog became ill and died, ________ made him very lonely.

[　　]