Before becoming the leading company for transferring remittances from the united states, what was the principal business of western union?

Western Union has been around over a hundred years, even though it wasn´t named like that before and its main business was connecting people across the United States and overseas through telegraph, its main activity until 1879 when telephone replaced telegraph and the company lost a sue againt BELL and decided to change its way to earn money starting offering money transferring service from and to the United States, being today one of the biggest financial service company all over the world. 

The answer i think is d