======================================================================
Mr. A was offered a number of positions in the company, ___of which were exactly what he was looking for.
======================================================================

1) few  2)both 3)none 4) all 

The correct answer for this question is (C) NONE.

As for me, of the two answers, none and all, what is more natural for the above sentence is very confusing to me. 

Would you explain why the "all" above can not match the answer?

Thanks in advance.