Four communication improvements included: the telephone the telegraph assembly line mail delivery trans-atlantic cable

The telephone, telegraph, mail delivery, and Trans-Atlantic Cable were all technologies for communication. The assembly line was not, it had nothing to do with communication, therefore that one does not belong, leaving you with the other four.

The correct answers are the following:

All these four communication improvements have meant a turning point when they were developed. On the other hand, the rejected option is not a communication improvement but an improvement in production and manufacturing activities. Assembly lines were also a turning point as they allowed to produce very large amounts of output, to reduce costs and to gain efficiency in production also due to reaching economies of scale.

the answer is title i subtitle b

it increase by 12% a year from 1812-1820