Question

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,

Answer 1

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

Options D and E can't be correct because of wrong idiom "conceived of the radio to be " rather it must be "conceived of radio as a tool "

Option A is not the right choice - because of the conception of as

Option B is also not correct because it is not clear as the wrong use of the pronoun "which" referring to telephone, private conversation or radio.

Option C is the best choice "conceived of" correct idiom, correct idiom " substitute for" meaning is clear "it" refers to the radio. Grammatically correct.