34. --Have you ever heard of an American president called Chester A.Arthur? --No, and he i

34.   --Have you ever heard of an American president called Chester A.Arthur?
--No, and he is not mentioned in my history book at all. He seems     .
A. to have been pletely forgotten                 B. having pletely forgotten
C. to have pletely forgotten                         D. pletely forgetting