On a rainy day I was driving north through Vermont, ______ I noticed a young man holding up a sign _____ “Boston”.

  A. where; reading      B. when; reading

  C. where; to read       D. when; to read

On a rainy day I was driving north through Vermont, ______ I noticed a young man holding up a sign _____ “Boston”.

1. A.
   where; reading
2. B.
   when; reading
3. C.
   where; to read
4. D.
   when; to read