I have $20 000 and I need $25 000,but my parents have promised to _______ the difference.

1. A.
   work out
2. B.
   come up
3. C.
   give out
4. D.
   make up

I have $20 000 and I need $25 000,but my parents have promised to _______ the difference.?

A. work out    B. come up     C. give out     D. make up?