Just as there was a Stone Age, an Iron Age and so on, we have been living for centuries in a
Paper Age, during which almost all information was kept and sent on paper; and so much of it is wasted after it has been used once that enormous numbers of trees have to be cut down every year to provide us with paper. But now, with the computer, enormous amounts of information can be stored and sent without any paper at all, using small discs or the Internet.
Computers have also made it possible to do very difficult calculations very much faster than any earlier machine could. Computers also allow one to send information to others anywhere in the world via the Internet and in turn to receive information back from them. One can send a very long message more quickly from England to Australia, for example, than from one's house to someone in the garden. Computers are not only used for writing; they can produce diagrams and pictures, and they can be used for playing games. One now sees them at airports and railway stations, in hotels and restaurants; in fact, almost everywhere where people gather.
The author seems to say that the invention of the computer is ______.

A. not so important as that of the steam and petrol engines
B. at least as important as that of the steam and petrol engines
C. less important than that of the steam and petrol engines
D. far more important than that of the steam and petrol engines