What were the key late-nineteenth-century technological innovations in communications, office productivity, and ocean transportation?

the key late-nineteenth-century tecchnological innovation in communication was : Phone
 Which allows us to contact our peers directly on the line without having to wait for weeks for the a latter.
 Technological innovation for productivity would be : A computer, Which allow us to stored a lot of files without having a mountain of paper lying on the floor of the office
 The ocean transportation innovation would be : An airplane which allow us to cross the continents within a shorter period of time

B,c and d are the answers