What Improvements Needed to Be Made to the Telephone Before

Multiple Choice

What improvements needed to be made to the telephone before it could be more widely adopted?

A) The number of voices carried on a single wire had to be increased; a government department had to be created to assign phone numbers.
B) The number of voices carried on a single wire had to be increased; the handset had to be made more comfortable.
C) Sound needed to be made easier to hear; the number of voices carried on a single wire had to be increased.
D) Sound needed to be made easier to hear; viewers had to be able to see the number of the person calling on the phone itself.