There are three girls in the room, ________ is Tom's sister.

1. A.
   the tallest of which
2. B.
   the tallest of whom
3. C.
   tallest of that
4. D.
   tallest of which

There are three girls in the room, ________ is Tom's sister.

A. the tallest of which                   B. the tallest of whom

C. tallest of that                        D. tallest of which

There are three girls in the room, ________ is Tom's sister.

There are three girls in the room, ________ is Tom's sister.