That passenger was very impolite to the conductor, ______, of course, made things even worse.

 That passenger was very impolite to the conductor, ______, of course, made things even worse.

A．who             B．which            C．what             D．that

That passenger was very impolite to the conductor, ______, of course, made things even worse.

1. A.
   who
2. B.
   which
3. C.
   what
4. D.
   that

 That passenger was very impolite to the conductor, ______, of course, made things even worse.

A. who       B. which       C. what      D. that

 That passenger was very impolite to the conductor, ______, of course, made things even worse.

A. who       B. which       C. what      D. that