请教GWD 11--10

No,112 GWD11-10:

Marconi’s conception of the radio was as a substitute for the telephone, a tool for private conversation; instead, it is precisely the opposite, a tool for communicating with a large, public audience.

A.       Marconi’s conception of the radio was as a substitute for the telephone, a tool for private conversation; instead, it is

B.       Marconi conceived of the radio as a substitute for the telephone, a tool for private conversation, but which is

C.       Marconi conceived of the radio as a tool for private conversation that could substitute for the telephone; instead, it has become

D.       Marconi conceived of the radio to be a tool for private conversation, a substitute for the telephone, which has become

E.       Marconi conceived of the radio to be a substitute for the telephone, a tool for private conversation, other than what it is,

Marconi’s conception of the radio was as a substitute for the telephone 这句话错在那里???